1 What calculationsare represented?

The first onehasbeendone foryou.

a)

15 + 5 = 20

b)

+ =

c)

+ =

d) Howmanyothernumberbonds to20 canyoumake using countersand ten frames?

Fact families – addition and subtraction bonds to 20

2 Complete the fact family.

a)15 + 2 = 17

17 = 15 + 2

2 + 15 =

= +

17 − 15 =

= −

− =

= −

b)

ExplainwhyRosie iswrong.

©WhiteRoseMaths2019

2 – 17 = 15 should be in the fact family.

3 Complete thenumber sentences for the part-wholemodel.

+ =

− =

+ =

− =

Are there anyothernumber sentences in thisfact family?

Talk about itwithapartner.

4 Thereare9 boysand 8girls ina class.

Complete thebarmodel to represent this.

9 8

Write the fact family for thebarmodel.

5 Circleany incorrect calculations.

3+7=10 10=3+7

7+3=10 10=7+3

10−7=3 7−3=10

3−10=7 7=10−3

Explain themistake thathasbeenmade.

6 Hereare somenumber cards.

Choose twonumber cardsandfind their total.

+ =

Write the fact family for this calculation.

Compareanswerswithapartner.

©WhiteRoseMaths2019

11

5 6

5 2 7 13 6