Today we will be learning: about multiplication and division that halving is the inverse of doubling.

We are going to count in multiples of Mental Activity

Try these multiplications. Work out the answer before each one disappears. 6 x 2 = 8 x 4 = 9 x 2 = 9 x 4 = 8 x 2 = 6 x 4 =

Now try these. Work out the answer before each one disappears. 7 x 2 = 5 x 4 = 11 x 2 = 11 x 4 = 5 x 2 = 7 x 4 =

Is there a useful strategy you could use to solve those problems?

Main Activity Today we are going to do more work on multiplication.

Count on in multiples of 5. What do you notice about the units digits? They are all 5 or 0.

5, 10, 15, 20, 25, 30, 35, 40, 45, 50 Which of these numbers are multiples of 10?

5, 10, 15, 20, 25, 30, 35, 40, 45, 50 Which of these numbers are multiples of 10?

What doubling fact do we already know that could help us to work out double 20? Double 2 = 4 So double 20 = 40

Now use this strategy to double these numbers

If we wanted to double 35, how could we do it? = = =10 70

Try these = = =

Put the numbers into the function machine one at a time Double it What comes out?

Group Work Work on the 5 and 10 times tables. Use function machines to double and halve numbers. Play games involving doubling.