Teach KS2 Children Division – What Is The ‘Chunking’ Method?

Filed in: Maths,

Division in many Primary Schools is taught using repeated subtraction. The 'chunking' method in Maths, uses repeated subtraction to find answers to division problems that use larger numbers, e.g numbers to 100 and/or over 100. It also helps children find remainders when dividing. A good, sound knowledge of  times tables facts in Maths, will help children use and understand the 'chunking' method, therefore regular time tables practice is essential.

Division Without Remainders.

Problem: 76 ÷ 2

Solution:   76
                   -20  (10 x 2)
                    56
                   -20  (10 x 2)
                    36
                   -20  (10 x 2)
                    16  (  8 x 2)      

Answer: 10 + 10 + 10 + 8 = 38     

Why is 10×2 used?
Many children will know their 10x tables and will be able to use this knowledge for the repeated subtraction. They are then left with 16 at the end, which is 8×2.

Division With Remainders.

Problem: 98 ÷ 6
 

Solution:  98
                   -60  (10 x 6)
                    38
                   -36  (  6 x 6)
                      2

Answer: 10 + 6 = 16 r 2 

In this example only one 10×6 is subtracted because once 60 is taken away from 98, only 38 is left.
The number nearest to 38 in the x6 tables is 36, therefore 36 is the number that is subtracted.
This leaves a remainder of 2.

Refining Division Methods – 'Chunking' Method.

Once children are happy and confident using the above method of dividing, they can start to refine and make the process quicker.  Again, the child's knowledge of times tables facts in Maths, will help them to understand and use the repeated subtraction (chunking method) more easily. Regular times tables facts practice is very important!

Problem: 457 ÷ 6

Solution: 457
               - 420   (70 x 6)
                   37
                –  36   (  6 x 6)
                     1

Answer: 70 + 6 = 76 r 1

This example shows how you can cut out the need to subtract and write down -60 (10×6)  seven times to reach the number 36.
A quicker way is to look at the number 457 and think 'Which number in the x6 tables is nearest to 457?'

 

 

 

Tip: Cover up the 7 in 457, this shows 45. Which number in the x6 times tables is nearest to 45? 42 is. 7×6 is 42. But because we are looking at numbers in the hundreds, we need to make sure the 0 is put into the working out, making it 420, which is 70×6.

The rest of the sum can then be worked out.

Practice Makes Perfect!

Use these worksheets to practice Maths and division using repeated subtraction – 'chunking method'.

Keystage 2 Division – How To Divide Using The Chunking Method. Maths Worksheet

Does your child need to learn their times tables facts?

Article: 5 Tips To Help Children Learn Their Times Tables
Worksheet: Times Table Square –  Activities For Learning Times Tables