How_To_Be_Good_At_Math

140 CALCULATING •^ EXPANDED SHORT DIVISION

Expanded short division

Short division is a method we use when the number we are dividing by (the

divisor) has only one digit. To make the calculation easier, we use expanded

short division. In this method, we subtract multiples, or “chunks”, of the divisor.

7

To try out expanded short division,

let’s divide 156 by 7.

First, we write the number we want

to divide (the dividend). In this case,

it’s 156. We draw a division bracket (like an

upturned “L”) around it. We put the divisor,

7, outside the bracket, to the left of 156.

Now we’re ready to begin dividing.

Expanded short division is just like

repeated subtraction, but instead of

taking away 7 repeatedly, we subtract

much bigger chunks of the number each

time. To start, we’ll take away 70, which is

10 groups of 7. So, we subtract 70 from

156, which leaves 86.

We have 86 left over, so we can

subtract another chunk of 70 from

it. That leaves 16. We’ve now subtracted

20 groups of 7 from 156.

156

You may find it

helps to label the

place values

Division

bracket

86 − 70 = 16

H T O

(^7156)
Draw a line and write
what’s left over here,
making sure you keep
the place values lined up
We write down
how many 7s
we’ve taken away
H T O
(7 × 10)
70
(^7156)
Record another
ten groups of 7
H T O
86
(7 × 10)
(7 × 10)
156 ÷ 7 =?
−
−
−
Expanded short division uses
repeated subtraction, which
we looked at on page 129.
1
70
86
70
16
140-141_Expanded_short_division.indd 140 29/02/2016 18:03