Year 4 - Maths
Use known facts from the 10 times table to solve problems involving the 9 times table
Represent counting in nines as the 9 times table
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils will represent counting in 9s as the 9x table explaining the relationship between adjacent multiples of 9. They will use known facts from the 10x table to solve problems involving the 9x table.
Lesson Summary
You will learn to use known facts from the 10 times table to solve problems involving the 9 times table.
Key Notes
- If 9 is equal to 10 subtract 1 then 9 groups of 15 is equal to 10 groups of 15 subtract 1 group of 15
- Facts from the 10 times table can be used to solve problems involving the 9 times table.
- 10 times a number and 9 times a number are adjacent multiples.
Vocabulary To Learn
- Array: An array is the layout of items (such as objects, numbers etc.) arranged in rows and / or columns.
Common Mistakes To Avoid
- Lack of fluency in 9 times tables and not understanding the problems.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
If 9 is equal to 10 subtract 1 then 9 groups of 15 is equal to 10 groups of 15 subtract 1 group of 15. Facts from the 10 times table can be used to solve problems involving the 9 times table.
2. Use this key word in a maths sentence and explain it clearly. 'Array'
An array is the layout of items (such as objects, numbers etc.) arranged in rows and / or columns. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Lack of fluency in 9 times tables and not understanding the problems. Correction: To clearly model highlighting key words of worded problems to understand the problem and the operation required for the calculation. Continue to use language stems such as 'If I know...' 'Then I know...,' to support mathematical thinking.
More Lessons In This Unit
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