5A Doubling and halving

What is double 10

• 1010

• 11

• 20

• 100

The answer is 20. Which questions give the answer 20? (choose 2)

• Double 10

• 10+10 =

• Half of 30

• 100 - 30

19 + 19 = ___

Half of 30 =

• 14

• 16

• 18

• 15

I know 17 + 17 = 34

So I know 170 + 170 = ____

I know 25 + 25 = 50

So I know that

250 + 250 = ___

Half of 60 = ___

Half of 70 = __

Half of 90 = __

If I know

6+6 = 12

Then I also know:

Choose two

• 30 + 30 = 60

• 60 + 60 = 120

• Half of 12 = 6

• 120 - 20 = 100