The Power of Place Value · Number Sense

Flexible Addition and Subtraction

Developing mental math strategies and exploring the relationship between addition and subtraction within 1000.

Key Questions

  1. 1How can we use the properties of numbers to make mental calculation easier?
  2. 2Why does the result of a subtraction problem represent the distance between two numbers?
  3. 3How can we prove that our answer is correct using a different strategy?

Ontario Curriculum Expectations

ON: Number - Grade 3ON: Algebra - Grade 3
Grade: Grade 3
Subject: Mathematics
Unit: The Power of Place Value
Period: Number Sense

Suggested Methodologies

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