This macro-enabled spreadsheet is designed to support learning how different memory addressing modes work in Computing. The addressing modes supported are Immediate, Direct, Indirect and Indexed. Clicking the ‘New question’ button clears any previous answers and generates a new base address and an offset for Indexed Addressing. The learner then enters the data that will be found using each of the addressing modes. Clicking the ‘Show answers’ button then reveals the correct answers. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This spreadsheet is designed to support learning how well algorithms of differing time complexities scale in Computing. By changing the size of the data set, n, the learner can see how well algorithms with Constant, Linear and differing Polynomial, Exponential and Logarithmic complexities scale, even with small data sets.

This macro-enabled spreadsheet is designed to support learning how a Binary Search works in Computing. It simulates a database with record keys in the range zero to the user’s choice of between ten and one million. After entering the record number to be found, the spreadsheet shows how each iteration of the Binary Search focusses in tighter and tighter on the required record until it is found. It also gives learners the opportunity to see how algorithms of logarithmic complexity O(Log n) scale, i.e. how doubling the number of records only adds one to the maximum number of searches required to find the target. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled spreadsheet is designed to practice converting between the number bases Decimal (Denary, Base 10), Binary (Base 2), Hexadecimal (Hex, Base 16) and Octal (Base 8) as used in Computing. There are four worksheets, each having questions converting from one of the number bases to the other three. Each worksheet generates ten questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals whether the answer is right or wrong. Changing an answer removes the marking until the button is clicked again. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled Excel spreadsheet contains three styles of simultaneous equation questions suitable for UK Key Stage 3 and GCSE sets or the equivalent. For each style, the ‘Generate questions’ button generates ten questions at a time. The solution to each question can be revealed individually by clicking the appropriate ‘Show answer’ button. Difference The x terms in both equations are the same positive integer and the simultaneous equations are solved by subtracting the bottom equation from the top equation. Addition The x terms in both equations are the same magnitude, but the top x term is positive, and the bottom x term is negative. The simultaneous equations are solved by adding the top and bottom equations. Balancing The simultaneous equations are solved by balancing either the y terms or the x terms and subtracting. Both methods are shown when the ‘Show answer’ button is clicked. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled Excel spreadsheet contains quadratic questions suitable for UK Key Stage 3 and GCSE sets or the equivalent. For each worksheet, the ‘Generate questions’ button generates ten questions at a time. The solution(s) to each question can be revealed individually by clicking the appropriate ‘Show answer’ or ‘Show answer(s)’ button. Factorising Quadratic expressions are created to be factorised. To vary the difficulty, the teacher can select whether the x² term is always 1, and whether or not the factors will always be integers. If the factors are not integers, they are given correct to two decimal places. Solving Quadratic equations are created to be solved. To vary the difficulty, the teacher can select whether the x² term is always 1, and whether or not the solutions will always be integers. If the solutions are not integers, they are given correct to two decimal places. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled spreadsheet is designed to practice unsigned integer binary addition and subtraction in Computing. Each worksheet generates ten questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals which bits are right and which are wrong. Changing an answer removes the marking until the button is clicked again. Both worksheets have space for the learner to place carry bits as part of their working. Also, the Addition worksheet allows for difficulty to be adjusted by selecting whether questions generate overflow or not which the learner then has to pick up, while the Subtraction worksheet provides space for the number to be subtracted to be Twos Complemented. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled Excel spreadsheet contains four Mathematics starter tasks suitable for UK Key Stage 3 and GCSE sets or equivalent. Odd One Out The purpose of this starter is to enable learners to explain the properties of numbers and develop their use of correct mathematical terminology. Three integers are generated between maximum and minimum values selected by the teacher. Learners are invited to select one of the three numbers and give a reason why it is the odd one out. For example, if the numbers were 6, 36 and 49: 6 is the odd one out because it is the only Perfect Number. 6 is the odd one out because it is the only one that is not a Square Number. 49 is the odd one out because it is the only one that is not a multiple of 2. 49 is the odd one out because it is the only one that does not have 2 as a factor. 49 is the odd one out because it is the only one that is not a multiple of 3. 49 is the odd one out because it is the only one that does not have 3 as a factor. 49 is the odd one out because it is the only one that is not a multiple of 6. 49 is the odd one out because it is the only one that does not have 6 as a factor. 49 is the odd one out because it is the only one that is a multiple of 7. 49 is the odd one out because it is the only one that has 7 as a factor. The ‘Another!’ button generates a fresh set of numbers. Ordering The purpose of this starter is to arrange six numbers into ascending order. To increase or decrease difficulty, the teacher selects the number range to use (a minimum of 0 and a maximum of 100), the number of decimal places to use (0 to 3), or whether to have a mixture of 0, 1, 2 and 3 decimal place values. Once the learners have filled in the answers, the 'Mark Them! button reveals which responses are correct and incorrect. Changing an answer removes the marking until the button is clicked again. The ‘Another!’ button generates a fresh set of numbers. Decimal Places The purpose of this starter is to round six three decimal place real numbers to one and two decimal places. To increase the level of difficulty the teacher selects the number range to use (a minimum of 0 and a maximum of 100). Once the learners have filled in the answers, the 'Mark Them! button reveals which responses are correct and incorrect. Changing an answer removes the marking until the button is clicked again. The ‘Another!’ button generates a fresh set of numbers. Sig Figs The purpose of this starter is to round six numbers to one, two and three significant figures, The teacher selects the number range to use: either four- and five-digit integers or 5 decimal place real numbers. Once the learners have filled in the answers, the 'Mark Them! button reveals which responses are correct and incorrect. Changing an answer removes the marking until the button is clicked again. The ‘Another!’ button generates a fresh set of numbers.

This macro-enabled spreadsheet is designed to practice converting from Decimal to Floating Point Binary as used in Computing, and vice-versa. There are two worksheets, one with questions converting from Decimal to Floating Point Binary, and one with questions converting from Floating Point Binary to Decimal. Learners are guided through the steps necessary to complete each type of question, namely: Decimal to Floating Point Binary Calculating the positive signed raw Binary; Twos Complementing to obtain the negative raw Binary, if required; Determining the distance the point floats; Determining the direction the point floats; Determining the positive Decimal value of the Exponent; Calculating the Binary value of the Exponent; Twos Complementing to obtain the negative Binary value of the Exponent if required; Working out the Mantissa; Giving the full Floating Point Binary. Floating Point Binary to Decimal Calculating the positive signed raw Binary; Working out the Mantissa; Working out the Binary Exponent; Twos Complementing to obtain the positive Binary value of the Exponent to determine its magnitude if required; Determining the Decimal value of the Exponent; Determining the distance the point floats; Determining the direction the point floats; Un-normalising the Binary Mantissa into its raw Floating Point form; Twos Complementing to obtain the positive Binary value of the raw Floating Point Binary Mantissa to determine its magnitude if required; Giving the Decimal value. The size of the Mantissa can be varied between 4 and 8 bits in size, and the Exponent can be either 3 or 4 bits in size. This both changes the question difficulty and also gives learners an opportunity to appreciate how altering the sizes of the Mantissa and Exponent affect the range of values which can be stored and the accuracy with which they can be represented. With the Binary Exponent, both types of question use the convention with negative Binary numbers whereby if only the Sign Bit is a 1, it represents both sign and magnitude. For example, with a signed 4 bit Binary number, 1000 represents -8 in Decimal. Each worksheet generates five questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals which steps of their answer are right or wrong. Changing an answer removes the marking until the button is clicked again. This worksheet is designed to be used prior to completing our ‘Endless Unguided Floating Point Binary Conversion question generator’ worksheet. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled spreadsheet is designed to demonstrate the ability to convert from Decimal to Floating Point Binary as used in Computing, and vice-versa. There are two worksheets, one with questions converting from Decimal to Floating Point Binary, and one with questions converting from Floating Point Binary to Decimal. The size of the Mantissa can be varied between 4 and 8 bits in size, and the Exponent can be either 3 or 4 bits in size. This both changes the question difficulty and also gives learners an opportunity to appreciate how altering the sizes of the Mantissa and Exponent affect the range of values which can be stored and the accuracy with which they can be represented. With the Binary Exponent, both types of question use the convention with negative Binary numbers whereby if only the Sign Bit is a 1, it represents both sign and magnitude. For example, with a signed 4 bit Binary number, 1000 represents -8 in Decimal. Each worksheet generates five questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals whether their answer are right or wrong, and the steps required to complete the question successful, namely: Decimal to Floating Point Binary Calculating the positive signed raw Binary; Twos Complementing to obtain the negative raw Binary, if required; Determining the distance the point floats; Determining the direction the point floats; Determining the positive Decimal value of the Exponent; Calculating the Binary value of the Exponent; Twos Complementing to obtain the negative Binary value of the Exponent if required; Working out the Mantissa; Giving the full Floating Point Binary. Floating Point Binary to Decimal Calculating the positive signed raw Binary; Working out the Mantissa; Working out the Binary Exponent; Twos Complementing to obtain the positive Binary value of the Exponent to determine its magnitude if required; Determining the Decimal value of the Exponent; Determining the distance the point floats; Determining the direction the point floats; Un-normalising the Binary Mantissa into its raw Floating Point form; Twos Complementing to obtain the positive Binary value of the raw Floating Point Binary Mantissa to determine its magnitude if required; Giving the Decimal value. Changing an answer removes the marking until the button is clicked again. This worksheet is designed to be used after completing our ‘Guided Floating Point Binary Conversion questions’ worksheet. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled spreadsheet is designed to demonstrate the ability to add and subtract Floating Point Binary numbers as used in Computing. There are two worksheets, one with addition, and one with subtraction. The following options can be selected: • The size of the Mantissa can be varied between 4 and 8 bits in size. This both changes the question difficulty and also gives learners an opportunity to appreciate how altering the size of the Mantissa affects the accuracy with which values can be represented. • The size of the Exponent can be either 3 or 4 bits in size. This both changes the question difficulty and also gives learners an opportunity to appreciate how altering the size of the Exponent affects the range of values which can be stored. • Both positive and negative Mantissae can be generated, or questions can be made simpler by allowing only positive Mantissae to be generated. • There is an option to emulate how some processors treat the Carry Bit as an additional Sign Bit in certain conditions, allowing learners to determine the circumstances when this happens and the effect it has on eliminating Overflow. With the Binary Exponent, both types of question use the convention with negative Binary numbers whereby if only the Sign Bit is a 1, it represents both sign and magnitude. For example, with a signed 4 bit Binary number, 1000 represents -8 in Decimal. Each worksheet generates five questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals whether their answer are right or wrong, and the steps required to complete the question successfully, namely: • Converting the two values from Floating Point form to raw binary; • Aligning the points of the raw binary values and padding out with additional Sign Bits and trailing zeroes as necessary; • Twos Complementing the bottom of the point-aligned values (subtraction only); • Performing the addition or subtraction of the point-aligned values; • Determining the Mantissa, or if Overflow has occurred; • Determining the Exponent, or if Overflow (the Exponent is a positive value too big to be represented in its selected number of bits) or Underflow (the Exponent is a negative value too big to be represented in its selected number of bits) has occurred; • Giving the full Floating Point binary string if possible, or stating it is impossible to do so if not; • Stating whether the Floating Point value has been truncated or not if it was possible to generate it. Changing an answer removes the marking until the button is clicked again. This worksheet is designed to be used after completing our ‘Guided Floating Point Binary questions’, ‘Unguided Floating Point Binary questions’ and ‘Guided Floating Point mathematics questions’ worksheets.

This macro-enabled spreadsheet is designed to practice signed integer binary addition and subtraction in Computing. Each worksheet generates ten questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals which bits are right and which are wrong. Changing an answer removes the marking until the button is clicked again. Both worksheets allow for difficulty to be adjusted by selecting whether negative numbers can form part of the question. They also have space for the learner to place carry bits and any necessary Twos Complementation as part of their working. The Addition worksheet further allows for difficulty to be adjusted by selecting whether questions generate overflow or not which the learner then has to pick up. NOTE: for this spreadsheet to work correctly, the copy of Excel in which it is running must allow macros to execute, and ‘Enable Content’ must be clicked when the spreadsheet is opened.

This macro-enabled spreadsheet is designed to practice adding and subtracting Floating Point Binary numbers as used in Computing. There are two worksheets, one with addition, and one with subtraction. Learners are guided through the steps necessary to complete each type of question, namely: • Converting the two values from Floating Point form to raw binary; • Aligning the points of the raw binary values and padding out with additional Sign Bits and trailing zeroes as necessary; • Twos Complementing the bottom of the point-aligned values (subtraction only); • Performing the addition or subtraction of the point-aligned values; • Determining the Mantissa, or if Overflow has occurred; • Determining the Exponent, or if Overflow (the Exponent is a positive value too big to be represented in its selected number of bits) or Underflow (the Exponent is a negative value too big to be represented in its selected number of bits) has occurred; • Giving the full Floating Point binary string if possible, or stating it is impossible to do so if not; • Stating whether the Floating Point value has been truncated or not if it was possible to generate it. The following options can be selected: • The size of the Mantissa can be varied between 4 and 8 bits in size. This both changes the question difficulty and also gives learners an opportunity to appreciate how altering the size of the Mantissa affects the accuracy with which values can be represented. • The size of the Exponent can be either 3 or 4 bits in size. This both changes the question difficulty and also gives learners an opportunity to appreciate how altering the size of the Exponent affects the range of values which can be stored. • Both positive and negative Mantissae can be generated, or questions can be made simpler by allowing only positive Mantissae to be generated. • There is an option to emulate how some processors treat the Carry Bit as an additional Sign Bit in certain conditions, allowing learners to determine the circumstances when this happens and the effect it has on eliminating Overflow. With the Binary Exponent, both types of question use the convention with negative Binary numbers whereby if only the Sign Bit is a 1, it represents both sign and magnitude. For example, with a signed 4 bit Binary number, 1000 represents -8 in Decimal. Each worksheet generates five questions every time the ‘Generate Questions’ button is clicked. Once the learners have completed a question, clicking the associated ‘Mark It’ button reveals which steps of their answer are right or wrong. Changing an answer removes the marking until the button is clicked again. This worksheet is designed to be used after completing our ‘Guided Floating Point Binary questions’ and ‘Unguided Floating Point Binary questions’ worksheets, and prior to completing our ‘Unguided Floating Point mathematics questions’ worksheet.