l.o.1 to be able to derive quickly division facts corresponding to tables up to 10x10

L.O.1

To be able to derive quickly division facts corresponding to tables up to 10x10

We are going to count on and back using different multiples.

10

9

8

7

6

5

4

3

2

1

0

L.O.2 To be able to use informal pencil and paper

methods to divide TU by U and HTU by U.

PROBLEM!

78 children will be placed in teams of 6.

How many teams will there be?

Q. What calculation do we need to solve this problem?

When you have decided how to do it work out the answer.

We need to do the division sum 78 ÷ 6.We can do this by chunking…

78 - 60 ( 10 x 6 )

18 - 18 ( 3 x 6 )

0

Q. How many 6’s have been subtracted?

78 ÷ 6 = 13

Q. What would be the answer if there had been 80 children?

Using chunking….

80 - 60 (10 x 6 )

20 - 18 ( 3 x 6 )

2 13 r.2

Using pencil and paper we write… 80 ÷ 6 = 13 remainder 2

Try this one with a partner:

There are 85 sweets to be shared equally among 7 children.

How many sweets does each child have? How many are left?

Using chunking…

85 -70 (10 x 7)

15 - 14 ( 2 x 7)

1 12 r.1

Using pencil and paper…85 ÷ 7 = 12 r.1

175 ÷ 7

In pairs discuss how you could calculate an answer to this.

Using chunking…

175

- 70 (10 x 7)

105

- 70 (10 x 7)

35

- 35 ( 5 x 7)

0

Answer = 25

In pairs discuss how you could calculate an answer to this:

148 ÷ 6

Using chunking…

148

- 60 ( 10 x 6)

88

- 60 ( 10 x 6)

28

- 24 ( 4 x 6)

4

Answer = 24 r.4

Try these:

134 ÷ 5

157 ÷ 6

119 ÷ 5

134 ÷ 5 134

- 50 (10 x 5)

84

- 50 (10 x 5)

34

- 30 ( 6 x 5)

4

Answer = 26 r.4

157 ÷ 6157

- 60 (10 x 6)

97

- 60 (10 x 6)

37

- 36 ( 6 x 6)

1

Answer = 26 r.1

119 ÷ 5119

- 50 (10 x 5)

69

- 50 (10 x 5)

19

- 15 ( 3 x 5)

4

Answer = 23 r.4

Q. What is

a quick way

to check

whether

the answer

to a

division

is correct?

To check whether the answer to a

division is correct we can use the

INVERSE operation.

LOOK…

57 ÷ 3 = 19

Q. Which two numbers should we

multiply to check whether this

is correct?

57 ÷ 3 = 19

To use the inverse operation

we should multiply 19 by 3.

19 x 3 = 57

LOOK…

175 ÷ 7 = 25

The inverse operation shows us

25 x 7 = 175

By the end of this lesson the children should be able to:

Use multiples of the divisor for TU ÷ U and HTU ÷ U calculations;

Check with the inverse operation.