C Curriculum Explorer
Mathematics·Addition & Subtraction·procedural

Adding within 100

Add within 100 using strategies based on place value, including adding a two-digit and one-digit number, and a two-digit and a multiple of 10

Suggested ages 6–7

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Learning journey

Your child is building strong foundations in addition and subtraction — learning to add and subtract numbers fluently within 20, understanding the relationship between these operations, and applying various mental strategies to solve problems.

Evidence of understanding

  • Calculate 46 + 7 using place value (46 + 4 + 3 = 53)
  • Calculate 38 + 40 = 78 using tens understanding
  • Relate the strategy to a written method and explain the reasoning

Assessment prompt

Can Adding within 100 work out sums like '47 + 8' or '35 + 50' by thinking about the tens and ones separately rather than counting up one at a time?

Standards alignment

1.NBT.4US · ccss-math

Add within 100

Common Core State Standards for Mathematics · 1