Target 10: Decimal Calculations

Target 10 deals with decimal additions, subtractions, multiplications and divisions.

Children will first add and subtract numbers that have matching decimal places, discovering that many can be performed mentally and others, although small numbers, need to be written. After all, decimal numbers can be 3-digit numbers, 4-digit numbers or more.

We then deal with the common addition and subtraction mistakes that occur when the two numbers do not have a matching number of decimal digits. For example, children must make sure that the 4 and 2 do not get added together in 13.4+9.92.

Decimal multiplication is sometimes too complex for primary school but not always. In Target 10, children will discover that multiplying by 0.5, 0.1, 0.2, 0.25 and 0.75 can be performed quite quickly using one or two alternative calculations.

For other decimal multiplications there is the option of estimating an answer then removing the decimal points before replacing it in the final answer. The Lattice method of long multiplication (see Target 6) also allows for decimal multiplication.

Finally, we will see that it is possible to divide by certain decimal numbers. Yes, it is possible that your students could answer 393.4÷0.7 or 310.8÷1.4 in a minute or two!

Each Target Practice workbook is divided into ten challenges, with target scores and time limits. The Target Extra section at the back of each book contains several repeat challenges, enabling your students to hit that target score should they miss out the first time.

This is a colourful 116-page PDF download, with explanation pages for each concept, and quick links to each chapter and the answer pages.

Not only that, this Target Practice workbook contains links to 72 minutes of teaching video, created by Catapult (only available to those who purchase the workbook).

Target 10’s ten steps are as follows:

Target 10a: Adding Matching Decimals

Target 10b: Subtracting Matching Decimals

Target 10c: Adding Non-Matching Decimals

Target 10d: Subtracting Non-Matching Decimals

Target 10e: Putting it all Together

Target 10f: Special Decimals for Multiplication

Target 10g: Multiplying Halves

Target 10h: Estimating & Multiplying Decimals

Target 10i: Decimals & The Lattice

Target 10j: Dividing Decimals

Launch their potential.

Trevor Veale

Target Practice author

Owner and full-time tutor at Catapult

Primary school teacher for nine years