Adding and Subtracting 100s

By the end of this unit, students will be able to:

1. add and subtract multiples of 100 to/from two-digit and three-digit numbers;
2. understand how adding 100 increases a number’s value, and subtracting 100 decreases a number’s value;
3. use place value concepts to visualize and solve addition and subtraction problems involving 100s;
4. apply the concept of adding and subtracting 100s to solve real-life and mathematical problems.

Curriculum Alignment: Year 3 Number: Addition and Subtraction

• Add and subtract numbers mentally, including:
  • a three-digit number and 1s.
  • a three-digit number and 10s.
  • a three-digit number and 100s.
• Add and subtract numbers with up to 3 digits, using formal written methods of columnar addition and subtraction.