 # Lob: I can use pencil and paper methods to divide TU by U and HTU by U.

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Lob: I can use pencil and paper methods to divide TU by U and HTU by U.

PROBLEM! 36 children will be placed in teams of 3. 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 36 ÷ 3. We can do this by chunking… 36 - 30 ( 10 x 3 ) 6 - 6 ( 2 x 3 ) 0 Q. How many 3’s have been subtracted? 36 ÷ 3 = 12 There will be 12 teams 3660 10 x3 = 30 2 x 3 = 6

PROBLEM! 52 children will be placed in teams of 4. 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 52 ÷ 4. We can do this by chunking… 52 - 40 ( 10 x 4 ) 12 - 12 ( 3 x 4 ) 0 Q. How many 4’s have been subtracted? 52 ÷ 4 = 13 There will be 13 teams 52120 10 x4 = 40 3 x 4 = 12

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 78180 10 x6 = 60 3 x 6 = 18

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

We need to do the division sum 80 ÷ 6. We can do this by chunking… 80 - 60 ( 10 x 6 ) 20 - 18 ( 3 x 6 ) 2 Q. How many 6’s have been subtracted? 80 ÷ 6 = 13 remainder 2 = 13 r2 80202 10 x6 = 60 3 x 6 = 18

Using chunking…. 80 - 60(10 x 6 ) 20 - 18 ( 3 x 6 ) 213 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) 112 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 ÷ 6 157 - 60(10 x 6) 97 - 60(10 x 6) 37 - 36 ( 6 x 6) 1 Answer = 26 r.1

119 ÷ 5 119 - 50(10 x 5) 69 - 50 (10 x 5) 19 - 15 ( 3 x 5) 4 Answer = 23 r.4

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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.

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