Every time this post is displayed a new set of questions about number bonds of 20 will be randomly generated in the table below.
There may be some duplicates, that can happen with random numbers. Anyway it is always a good idea to ask the same question more than once as you may not get the same answer each time.
What are number bonds?
This post explains number bonds in more detail but basically the number bonds of a particular number are all the pairs of smaller numbers that add up to that number. The questions in the table below should make things clear.
The worksheets use the following alternatives for adding
 +
 plus
 add
 and
and the following alternatives for subtracting
 –
 minus
 subtract
 takeaway
 less
20

minus

3

=

?

?

+

8

=

20

4

plus

?

=

20

?

+

8

=

20

?

plus

20

=

20

12

+

?

=

20

?

add

5

=

20

?

+

13

=

20

20

takeaway

?

=

16

9

plus

?

=

20

20

subtract

19

=

?

?

add

0

=

20

?

and

13

=

20

20

less

?

=

6

?

and

15

=

20

Number Bonds Worksheets Spreadsheet
Here is an Excel spreadsheet which will generate Number Bonds Worksheets
There are separate posts for number bonds of 9, 10 and 20 but all link to the same spreadsheet which has 3 worksheets in it.
Why Bother To Learn Number Bonds?
One reason is that children are taught number bonds and so will be expected to answer questions on them.
It’s just another way to practice addition and subtraction.
Learning number bonds of 10 and 20 help learn how to to arithmetic with more than one column.