Starter quiz
- Which factor has been partitioned using the distributive law in the second expression below? 5 × 11 = 5 × 10 + 5 × 1
- 5
- 11 ✓
- 8
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- 50 + 77 = ______
- '127' ✓
- 57 + 65 = ______
- '122' ✓
- Which of the following expressions represents the total number of pencils if I have 6 pots of 5 pencils and 6 pots of 8 pencils?
- 6 × 6 + 5 × 8
- 6 × 5 + 6 × 8 ✓
- 6 × 5 + 6 × 5
- 6 + 5 + 6 + 8
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Which of the following expressions is the array representing?- 4 × 10 + 3 × 10
- 7 + 6 + 7 + 3
- 7 × 6 + 7 × 3 ✓
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- Double 81 is ______
- '162' ✓
Exit quiz
- Which of the following expressions is equivalent to 8 × 16?
- 8 × 11 + 8 × 4
- 8 × 10 + 8 × 6 ✓
- 8 × 12 + 8 × 5
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What is the missing number in the array shown?- '6' ✓
Use the grid model to help solve 7 × 16 by finding two partial products and combining them. 7 × 16 = ______- '112' ✓
- Solve 18 × 8 = ______ using the distributive law.
- '144' ✓
- Solve 6 × 19 = ______ using the distributive law.
- '114' ✓
- Which of the expressions below is not equal to 18 × 11?
- 10 × 11 + 8 × 11
- 10 × 10 + 8 × 1 ✓
- 11 × 20 − 2 × 11
- 9 × 11 + 9 × 11
- 11 × 9 + 11 × 9
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Worksheet
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Presentation
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Lesson Details
Key learning points
- If you know the 3 and 10 times tables you can work out the 13 times table.
- If you know the 10 times table you can work out the 20 times table.
- If you know the 5 and 8 times tables you can work out the 16 times table.
Common misconception
Pupils may think that there is only one strategy for finding a solution and struggle to see that there is more than one way of partitioning a factor.
Spend some time discussing how many combinations of partitioned factor you could use with the distributive law and evaluate each combination for efficiency. This would be a worthwhile guided group task.
Keywords
Partition - Partitioning is the act of splitting an object or value down into smaller parts.
Distributive law - The distributive law says that multiplying a number by a group of numbers added together is the same as doing each multiplication separately.
Partial product - A partial product is any of the multiplication results we get leading up to an overall multiplication result.
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