(Almost) unlimited, NO-PREP, differentiated sets of Maths worksheets. At the click of a button all numbers (and visuals ) are randomized, creating a new worksheet with different numbers .... as many times as you want with answers automatically generated every time. Check out one of the Freebie samplers to see how they work.
(Almost) unlimited, NO-PREP, differentiated sets of Maths worksheets. At the click of a button all numbers (and visuals ) are randomized, creating a new worksheet with different numbers .... as many times as you want with answers automatically generated every time. Check out one of the Freebie samplers to see how they work.
Bridging through 100s encourages students to develop strong mental math skills by breaking down numbers into smaller more manageable parts.
Students get to visualize the connection between different place values and understand the concept of regrouping or carrying over.
It also provides students with an alternative approach to addition rather than relying completely on the standard algorithm. This strategy can be particularly beneficial for visual learners.
Worksheets 1 & 2 contain visual support to help introduce this topic.
Worksheet Set 1
First addend: Multiples of ten between 100 to 900
Second addend: Multiple of 10 between 90
Worksheet Set 2
First addend: Multiples of ten between 100 to 900
Second addend: Between 11 and 99
Worksheets Sets 3 & 4
These follow the same range of numbers as above but the pupils can now choose how they lay out their workings to demonstrate their understanding of addition through bridging.
All Worksheets are Dynamic: At the click of a button all the numbers are randomized providing you with (an almost) unlimited set of questions for classwork, revision, homework, assessments etc.
Answers are automatically generated every time for all Worksheets.
There is a Teaching Page with an unlimited number of randomly generated questions covering the graphic layout of Worksheet Set 1 and 2 designed for use with the Interactive whiteboard to help you introduce or review the topic with your class or on a PC or Mac for one-to-one tuition.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
You may also like:
Subtract by bridging through 100s up to 1000
Add bridging through 10 up to 100 Worksheets +
Subtracting by bridging through 10s up to 100
UK National Curriculum. Year 3 Programme of Study:
Number - Addition and Subtraction.
Add and subtract numbers with up to three digits, using formal written methods of columnar addition and subtraction
This is a no frills set of Worksheets providing an (almost) endless source of practicing column addition and subtraction of two, three or four 3-Digit numbers, differentiated to help introduce regrouping using the standard algorithm.
The first set of worksheets has adding & subtracting a 2-digit number from a 3-digit number can serve as a useful interim step between adding & subtracting 2-digit numbers and adding & subtracting 3-digit numbers.
Add a 3-Digit and a 2-Digit number & Subtract a 2-Digit from a 3-Digit number
This preliminary set of worksheets serves as a useful interim step between adding & subtracting 2-digit numbers and adding & subtracting 3-digit numbers.
No regrouping
Regrouping I - Units only
Regrouping II -Units and tens
Add two 3-Digit numbers
Regrouping I - Units only
Regrouping II -Units and tens
Regrouping III -Units, tens and hundreds
Add more than two 3-Digit numbers
Adding three 3-Digit numbers
Adding four 3-Digit numbers
Subtraction with two 3-Digit numbers
No regrouping
Regrouping I - Units only
Regrouping II - Units and tens
This will give you a choice of differentiating from the very start, or setting the level of work for the whole class.
A choice of formats
All the sets worksheets listed above come in 2 formats
The questions are laid out ready to work on with the numbers in the vertical format and the answer line ready to fill in.
The questions are presented in the horizontal format so that your students have to properly align the digits based on their place values, which is essential for accurate addition & subtraction.
(almost) Unlimited Worksheets ?
Yes ! At the click of a button all numbers are randomized, and will therefore change every time so you can create as many different worksheets for classwork, homework, revision, preparing for assessment, review before moving on to 3-digits, etc.
Answers are automatically generated every time.
No-Prep Worksheets
These are straightforward no-prep worksheets that require no extra work. Simply CLICK-PRINT AND GO. This makes them ideal to have printed and ready for a replacement teacher if needed.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
You may also like:
Add and subtract 2-digit numbers with & without regrouping
or
Add, Subtract 2 and 3-Digit Numbers formal and informal BUNDLE
An introduction into sharing with ratio using the bar model as an ideal visual aid.
Watch the video here for a quick tutorial on how to use these resources
There is a teaching resource designed to be used on an Interactive Whiteboard or on a PC or Mac for one-to-one tuition.
This is accompanied by a set of differentiated worksheets.
Pupils are asked to share a quantity in a given ratio. A bar of the correct number of parts is created and pupils can either color in the bar in the ratio given and / or calculate the amount to go in each part.
Another set of questions is based on being given the ratio & one of the final answers with the aim to find the initial quantity.
For added differentiation the totals to be shared are:
Level 1: Under 100
Level 2: to 1000 in multiples of 10
Level 3: to 1000
The Teaching Resources are interactive and the Worksheets are dynamic which means that at the click of a button the numbers in the questions are randomised. Answers are provided every time.
This resource works with the official Adobe Acrobat Reader on Windows or Mac computers.
For more information about teaching Ratio understanding
This "Dynamic PDF Worksheet " contains a mix of randomly generated addition and subtraction questions up to 20 , with pupils being asked to find the addend, minuend, subtrahend or sum. Answer are revealed at the click of a button. You can use this one page of exercises as many times as you need for classwork, homework or revision and the questions will change every time.
Click on the “HELP” button for further instructions.
Note
*This resource works with the official Adobe Acrobat Reader on Windows or Mac computers.
This set of resources covers addition and subtraction up to 1000 with the visual aid of dienes.
There are 8 sets of worksheets for both addition and subtraction, making 16 in total :
Addition
Worksheet 1 a & b. No exchange or regrouping .
Worksheet 2 a & b. Exchange of units (units add up to more than 10)
Worksheet 3 a & b. Exchange of 10s( 10s add up to more than 100)
Worksheet 4 a & b. Exchange of 10s and units, both 10s and units need regrouping.
At each level:
Worksheets a: * both numbers to be added are represented by numbers and dienes, so the dienes are essentially a support tool.
*- Worksheets b: *pupils have to deduce the two numbers to be added from the dienes blocks and then do the sum.
Subtraction
Worksheet 1 a & b No exchange, regrouping or borrowing .
Worksheet 2 a & b. Exchange 10 into ten units
Worksheet 3 a & b Exchange 100 into 10 tens
Worksheet 4 a & b. Exchange 10 into ten units and 100 into 10 tens
At each level:
Worksheets a: the first numbers is represented by a number and dienes, so the dienes are basically a support tool
Worksheets b: pupils have to deduce the first number from the dienes blocks and then do the subtraction.
The questions on each of the worksheets can be randomised at the click of a button, so the one resource can be used any number of times for classwork, revision, homework, assessments etc.
An answer sheet is produced every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
To get a more detailed view of these resources and to try out a limited version of one of the Worksheets go to PREVIEW: Addition & Subtraction to 1000 with Dienes
This "Dynamic PDF Worksheet " contains a mix of randomly generated addition and subtraction questions up to 10 , with pupils being asked to find the addend, minuend, subtrahend or sum. Answer are revealed at the click of a button. You can use this one page of exercises as many times as you need for classwork, homework or revision and the questions will change every time.
Click on the “HELP” button for further instructions.
Note
*This resource works with the official Adobe Acrobat Reader on Windows or Mac computers.
A bundle of resources to learn and practice reading Roman numerals and converting between Roman Numerals and numbers.
You have 4 levels to choose from with number ranges
1-20
10-100
100-1000
1000-3999
The Worksheets are dynamic which means that at the click of a button the numbers in the questions are randomised providing an (almost) unending set of questions.
Worksheet 1
Convert Numbers to Roman Numerals at the 4 levels listed above.
Worksheet 2
Convert Roman Numerals to Numbers at the 4 levels listed above.
The Teaching Resources are interactive which means that at the click of a button the numbers in the questions are randomised providing an (almost) unending set of examples.
They are designed as a whole class for use with an Interactive Whiteboard or on a computer for one to one tuition. Ideal for introducing this topic and a preparation for the Worksheets.
Teaching Page 1
Convert Numbers to Roman Numerals at the 4 levels listed above.
Teaching Page 2
Convert Roman Numerals to Numbers at the 4 levels listed above.
To get a more detailed view of these resources and to try out a limited version of a Worksheet go to PREVIEW: Roman Numerals
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
UK National Curriculum.
Year 5 Programme of Study Number.
Number and Place value.
Read Roman numerals to 1000 (M) and recognise years written in Roman numerals.
Percentage Bar Graphs provide visual support to help introduce percentages in an informal way by building on the equivalence of 50%, 25% & 75% and their fractions 1/2, 1/4 & 3/4 plus the knowledge that 10% =1/10 and 1/10th of any multiple of 10 or 100 can easily be found by removing the last zero of the number.
From this starting point pupils can then proceed to calculate multiples of 5% or 1% of quantities.
The Worksheets and Teaching Pages are set at 5 levels
10%, 25%, 50%, & 75% of multiples of 100
10%,20%,30% …90%, of multiples of 10
10%,20%,30% …90% of multiples of 100
5%,10%,15% … 95% of multiples of 10
Any percentage of multiples of 100
Answers will always be whole numbers.
The Worksheets are Dynamic and the Teaching Pages Interactive so that at the click of a button the percentages and quantities are randomised providing endless opportunities to practice at each and every level.
To get a more detailed view of these resources and to try out a limited version of the Worksheets go to PREVIEW: Introducing Percentages with Visual Support
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
A no frills set of (almost) unlimited differentiated worksheets for practicing addition and subtraction of two decimals numbers to the tenths, hundredths or thousandths using the standard algorithm.
Each worksheet has 12 questions laid out in the vertical format. They are divided into 18 sets:
Sets 1 to 9 - Addition and Subtraction
Units to 1 dp
Units to 2dp
Units to 3dp
Tens to 1dp
Tens to 2dp
Tens to 3dp
Hundreds to 1dp
Hundreds to 2 dp
Hundreds to 3dp
Sets 10 to 12 - Addition of 3 decimal numbers
Units to 1dp
Tens to 2dp
Hundreds to 3dp
Sets 13 to 15 - Addition of 4 decimal numbers
Units to 1dp
Tens to 2dp
Hundreds to 3dp
Sets 16 to 18 - Addition of 2 decimal numbers - find the missing digits
Units to 1dp
Tens to 2dp
Hundreds to 3dp
Why (almost) Unlimited Worksheets ?
At the click of a button all numbers are randomized, and will therefore change every time so you can create as many different worksheets as you need for classwork, homework, review, preparing for assessments, or just simply practice at any time to keep the skill alive throughout the whole year.
No-Prep Worksheets
These are straightforward no-prep worksheets that require no extra work. Simply CLICK-PRINT AND GO. This makes them ideal to have printed and ready for a replacement teacher if needed.
Answers are automatically generated every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
This set of (almost) unlimited Worksheets provides practice with adding and subtracting with 4 digit, 5 digit and a mix of 3,4 & 5 digit numbers with the numbers ready laid out in columns in order to use the standard algorithm.
Why (almost) Unlimited Worksheets ?
There are 6 basic differentiated templates, BUT, at the click of a button all numbers are randomised, and will therefore change every time so you can create as many different worksheets for classwork, homework, review, preparing for assessments, or just simply practice at any time to keep the skill alive throughout the whole year.
Answers are automatically generated every time.
UK National Curriculum
Year 4 Programme of Study
Addition and Subtraction
Add and subtract numbers with up to 4 digits using the formal written methods of columnar addition and subtraction where appropriate
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
Students compare two 3-Digit, 4-Digit, 5-Digit or 6-Digit numbers based on the meaning of the digits in each place within the number using the symbols <, =, or >.
Students must first indicate which digit in each number is determining their choice of <, = or >.
For each of the 4 sets of worksheets ( 3-Digit, 4-Digit, 5-Digit or 6-Digit numbers) there are 3 choices of presentation:
Numbers color coded to help with comparing the same size numbers (100s, 1000s etc) and are shown in a Place Value Table.
Numbers in a Place Value Table (no color coding).
Numbers without Place Value Table.
This will give you a choice of differentiating from the very start.
How many worksheets are in each set ?
Almost Unlimited. At the click of a button all numbers are randomised, so you can create as many different worksheets as you need for classwork, homework, revision, preparing for assessment, fillers etc and the numbers will change every time.
Your students will never run short of new worksheets to practice with.
Answers are automatically generated every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
Worksheets for practicing multiplying monomials, binomials, trinomials, and polynomials with four or more terms, with and without exponents.
Every Worksheet has 12 questions,which start simple but then develop gradually with questions 11 & 12 being more challenging. The 6 Sets are also arranged in an order that will hopefully help you to plan building the students’ knowledge, skills and confidence with multiplying polynomials.
By being able to randomise the numbers in the questions at the click of a button you will be able to generate sufficient worksheets for as much practice throughout the year as is needed to keep the skills alive.
Worksheet Set 1
Students are asked to multiply simple monomials by (mainly) binomials, with some tri- & a quadri- nomial. There are no exponents to calculate.
Worksheet Set 2
Students are required to multiply binomials by a monomial, moving a stage further to include exponents in each term.
Worksheet Set 3
This set involves multiplying two or more monomials each with a number of variables with exponents.
Worksheet Set 4
Students now practice multiplying two binomials which will include calculating multiplying variables with exponents, plus the added step of needing to combine like terms to obtain the final answer.
Worksheet Set 5
This Set contains questions that include multiplying binomials by trinomials, trinomials by trinomials and trinomials raised to the power of 2 and 3 and students will practice combining like terms.
Worksheet Set 6
This has an extra element in that instead of only using the standard algorithms for multiplying polynomials there is an alternative using Pascal’s triangle as a way to calculate binomial terms raised to various powers through recognising the symmetry of the powers and building of the coefficients for each term. There is additional support material for this set.
Answers are automatically generated every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
This collection contains Worksheets and Teaching Pages on multiplying 2-digit, 3-digit, 4-digit and 5-digit numbers by 1-digit numbers using the standard algorithm. It will provide you with all the levels you should ever need to cover this topic for pupils who need a gentle start with 2-digit numbers to the more challenging worksheets with 5-digit numbers.
Differentiation is easy and straightforward. At the click of a button you can create a whole worksheet focussed on multiplying a 2,3,4 or 5-digit number by any single digit from 2 to 9 or choose from 5 levels of a mix of multipliers - 2,3,4,5 or 3,4,5,6 or 4,5,6,7 or 5,6,7,8 or 6,7,8,9.
Exactly how many worksheets are there?
Virtually unlimited. You will have a minimum of 52 worksheets as described above. e.g a page on multiplying 2-digit numbers by 3, or a page dedicated to multiplying 3-digit numbers by 8 etc.
BUT click any button all numbers are randomised, creating a brand new worksheet. This means that you can have as many different worksheets for classwork, homework, review, preparing for assessments, or just simply practice at any time to keep the skill alive throughout the whole year.
Answers are automatically generated every time.
The Teaching Pages when projected onto a screen or interactive whiteboard allows you to go through the standard algorithm for multiplication showing each step of the process to your class. You begin by choosing the multiplier ( 2 to 9) then when you press one of the randomising buttons it changes the multiplicand, so you have an endless set of examples to practice with. As you enter each digit in the answer line you get instant feedback as to whether it is correct or not.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
Year 2 programme of study: Number – multiplication and division - Recall and use multiplication and division facts … including recognising odd and even numbers.
Learning to recognise and identify even and odd numbers is one of the simplest ways to start exploring patterns in numbers. Beginning with counting and pairing objects it develops to recognising even and odd numbers according to the last (unit) digit in a number whatever it’s size.
This pack includes (almost) unlimited printable Worksheets and Digital Teaching Resources.
Worksheets Set 1
Up to 14 objects either in columns or arranged randomly, practicing counting in pairs and determining whether the number is even or odd.
Worksheets Set 2
Pupils use this worksheet to recognise even and odd numbers by simply looking at the last digit.
There are two levels; The first contains numbers up to 100, and the second, for an extra challenge, numbers up to 1000
How is it possible to have (almost) Unlimited Worksheets ?
At the click of a button all numbers or numbers of objects are randomised, and will therefore change every time so you can create as many unique worksheets for classwork, homework, review, preparing for assessments, preparing different worksheets for groups within your class or just simply practice at any time to keep the skill alive throughout the whole year.
Answers are automatically generated every time.
Digital Teaching Material
These are designed to help you introduce the content of the worksheets to the whole class on an Interactive Whiteboard, or on a PC or Mac for 1-1 tuition and again you have (almost) unlimited examples to practice with.
Digital Teaching Page 1
Use pairing and/or counting, with objects in lines and arranged randomly (supports Worksheets Set 1)
Digital Teaching Page 2
Using 4 buttons you can randomly generate numbers at 4 levels: up to 30, 50, 100 or 1000 and get pupils to recognize whether they are even or odd by looking at the last digit. (supports Worksheets Set 2)
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
A fun way to practicing adding at 4 different levels with an (almost) unlimited number of Worksheets together with a self checking Interactive Teaching Resource for the whole class engagement on an Interactive Whiteboard or on a PC/Mac computer for one-to-one tuition.
Practice addition at 4 levels.
Addition up to 10
Addition up to 20
Addition up to 50
Addition up to 100
Differentiating the Worksheets
There are 4 addition squares on a page. You can set the range of numbers on each one individually, so you could have 4 number squares up to one level, a mix of 4 levels etc.
How many worksheets are there ?
All the numbers in each square are randomized at the click of a button which means you have an (almost) endless set of worksheets that could be used for classwork, homework, revision, tests etc.
**Answers **are automatically generated every time.
Note
This resource works with the official Adobe Acrobat Reader on Windows or Mac computers.
Divide multi-digit whole numbers by 1 & 2-digit divisor with & without remainders. Do your pupils need practice with a specific one-digit divisor ? Start with dividing 3-Digit by 1-Digit numbers without remainders, and step by step, go as far as you want your students up to dividing 5-Digit by 2-Digit numbers with remainders.
This pack has virtually unlimited Worksheets that require no preparation with 5 basic levels of differentiation, multiple other options in between, with or without remainders, with or without visual support.
5 levels of Differentiation
ALL with or without remainders
ALL with or without graphic support
Level 1: 3-digit numbers divided by a 1-digit number.
You can select a single divisor from 2 to 9, or have a page of mixed divisors
Level 2: 4-digit numbers divided by 1-digit numbers
Same choice of divisor as with Level 1.
Level 3: 5-digit numbers divided by 1-digit numbers
Same choice of divisor as with Level 1
Level 4: 5-digit numbers divided by a multiple of 10, from 10 to 90.
You can select a single divisor from 20 to 90, or have a page of mixed divisors
Level 5: 5-digit numbers divided by a number from 20 to 99.
Separated into 9 unique worksheets - 20-29, 30-39 … to 90-99
With or Without Visual Support
Worksheets are presented in two ways:
Simply with the divisor dividend and the space ready for the quotient
or
With the above plus the scaffolding for each step of the process, with arrows indicating the numbers to be drawn down.
How can there be virtually unlimited Worksheets ?
At the click of a button all the numbers are randomized providing you with a new set of questions for every level, so the same one resource which could be used for classwork, revision, homework, and practice all the year round.
FULL Solutions
Contains every step of the standard algorithm towards the solution. This for ALL Worksheets.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
Compare two fractions with different numerators and different denominators using visual fraction models leading to using a numerical method by finding a common denominator.
Reviewing earlier work
Whilst the content of these worksheets centres around fractions with different numerators AND denominators they begin with a review of comparing fractions with the same denominator or same numerator with the number line or rectangle bar. There is also a worksheets with purely numerical questions, but you may want to leave this until after beginning the ‘Investigation’.
Comparing fractions with 1/2
Again you have the same visual models as above, but you can choose whether the range of values of the denominators are from 3 or 10 or from 8 to 20.
Investigating patterns when comparing patterns
Here you could decide to investigate an alternative way to compare the fractions above by looking for any simple patterns in the results obtained so far that will allow your students to answer questions on comparing fractions without the need for visual models or a numerical method.
Comparing fractions with different numerators and different denominators
We now get to the core of the topic.
There are 3 levels, all with the choice of using the number line or rectangle bars.
Level 1:
Denominators are between 3 and 10
Level 2:
Denominators are between 3 and 20, but one is a multiple of the other. Here, it may be useful to refer back to the work done on Equivalent fractions as a double check on the answers could be done numerically.
Level 3:
Denominators are between 3 and 20
Transition from visual models to a numerical method
At this point in the process there needs to be a transition from using visual aids to a numerical approach which students will be using in the future.
Students get to see that the easiest way to compare two fractions is if they have the same denominators, then there is only the numerators to think about.
This is explained firstly through using a visual fraction model which is then linked to the idea of creating a common denominator between the two fractions by multiplying the 2 denominators together (all explained in the Guide).
Numerical Worksheets
There are 6 basic worksheet templates here:
Numerators or Denominators the same
Comparing fractions to 1/2
Compare Fractions (1) - Denominators from 3 to 12
Compare Fractions (2) - One Denominator is a multiple of the other
Compare Fractions (3) - Denominators from 3 to 20
Compare Fractions (4) - Denominators from 8 to 20
How many worksheets are there in total ?
Lots and lots …
Answers are automatically generated every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
An Interactive PDF Teaching Resource AND Dynamic PDF Worksheet
The minuends and subtrahends are randomised at the click of a button and you can choose from 6 ranges of numbers:
1- 10
1 - 20
1 - 50
1 - 100 in 10s
1 - 500 in 10s
1 -1000 in 10s
The Teaching Resource is designed to be used by teachers and pupils on an Interactive Whiteboard or on a PC/Mac computer for one-to-one tuition. Ideal as a warm up activity at the start of a lesson or game at the end.
The Dynamic PDF Worksheet provides 2 Subtraction Squares on one page, (again with randomisation of numbers in the same range as on the Teaching Resource), that you can print out for the pupils.
Answers are viewable for both the above resources.
A Help Guide and is included.
Note
*This resource works with the official Adobe Acrobat Reader on Windows or Mac computers.
This is one of 16 Sets of (almost) unlimited differentiated worksheets on dividing decimal numbers using the standard algorithm. In this Freebie sampler students get practice dividing of Hundreds to 2 decimal places by 1-digit whole numbers.
(Almost) Unlimited worksheets ?
Yes. At the click of a button all numbers are randomized, creating a new worksheet with different numbers, meaning you can use this one resource as many times as needed throughout the year to consolidate the skills and knowledge with a brand new worksheet every time.
No-Prep Worksheets
This is a straightforward no frills, no-prep, worksheet that require no extra preparation on your part. Simply CLICK-PRINT AND GO. Ideal to have printed and ready for a replacement teacher or end of lesson activity if needed.
Answers are automatically generated every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
When you download this Freebie you will also be able to see the Preview of the whole 16 Set Resource which can be found at:
Decimal Division - Standard Algorithm - Full Solutions
This is one worksheet from a of 8 Sets of (almost) unlimited differentiated worksheets covering addition and subtraction of 4 -Digit numbers using the standard algorithm.
In this sample worksheet, students will be able to practice adding 4 digit numbers with the question laid out in the vertical format ready to practice the calculation with regrouping.
(Almost) Unlimited worksheets ?
Yes. At the click of a button all numbers are randomized, meaning you can use this one resource as many times as needed throughout the year to consolidate the skills and knowledge needed at this level. You could even give every student their own unique set of questions !!
No-Prep Worksheets
Simply CLICK-PRINT AND GO. This is a no frills, no-prep, worksheet that requires no extra preparation on your part. Ideal to have printed and ready for a replacement teacher or end of lesson activity if needed.
Answers are automatically generated every time.
Note
These resources work with the official Adobe Acrobat Reader on Windows or Mac computers.
When you download this Freebie you will also be able to see the Preview of the whole 8 Set Resource which can be found at:
https://www.tes.com/teaching-resource/add-and-subtract-4-digit-numbers-standard-algorithm-13004490