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Year 1 - Maths

Counting patterns within a decade

Pattern in counting from 20 to 100

Unit Summary

In this unit pupils will extend their learning by counting to 100. They will explore the pattern in counting and focus on the end of the decade and the start of the new decade numbers. 

Lesson Summary

You will learn to notice the patterns in the numbers when counting up to 100.

Key Notes

  • You can use the patterns in the one hundred square to help you count to and from 100
  • The one hundred square is split into rows and these can help you count.
  • All the numbers in a row start in the same way except the decade number at the end.

Vocabulary To Learn

  • Row: A straight line of numbers, objects etc, arranged horizontally.
  • Pattern: A repeated arrangement of numbers, colours or shapes which are related to each other in some way or linked by a certain rule.
  • Decade: A set of 10 numbers, all beginning with the same number of tens, e.g. 20,21…29.

Common Mistakes To Avoid

  • Confusion when counting select rows on a one hundred square, e.g. children may not use the end of the number (the ones) to help them count accurately, or may say the row ending in 40 is the 'forties'.

3 Quick Questions (With Answers)

1. Solve this in steps: explain the method from this lesson and why each step matters.

You can use the patterns in the one hundred square to help you count to and from 100. The one hundred square is split into rows and these can help you count.

2. Use this key word in a maths sentence and explain it clearly. 'Row'

A straight line of numbers, objects etc, arranged horizontally. Use this word when showing your method, then check your final answer is reasonable.

3. Spot and fix this common maths mistake.

Mistake: Confusion when counting select rows on a one hundred square, e.g. children may not use the end of the number (the ones) to help them count accurately, or may say the row ending in 40 is the 'forties'. Correction: Label 'decades' throughout the lesson, and model errors in counting within these so that children get used to hearing when the count doesn't sound right.

More Lessons In This Unit

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