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Overview
Grade 2 Math
B2. Operations
10. B2.4 Addition and Subtraction
10.19 Using objects to subtract up to 100
Using Objects to Subtract Up to 100
Discover how counters and base-ten blocks make subtracting two-digit numbers up to 100 easy to see and understand.
What You'll Learn
Model subtraction by physically removing objects such as counters or blocks from a starting group
Represent two-digit numbers with tens blocks and ones blocks before taking any away
Cross out the amount being subtracted to see what remains, for example \( 52 - 27 = 25 \)
Regroup a tens block into ten ones whenever there are not enough ones to remove
Compare object-based subtraction with other strategies such as number lines and counting
Check the answer by adding the difference back to the number that was subtracted
What You'll Practice
1
Choosing the correct subtraction sentence from pictures showing objects
2
Counting remaining objects after subtraction is shown visually
3
Matching images with groups of items to their subtraction equations
Why This Matters
Using objects to visualize subtraction builds your number sense and helps you understand what subtraction really means. This concrete approach makes mental math easier and prepares you for solving word problems where you need to picture the situation.
This Unit Includes
Practice exercises
Learning resources
Skills
Subtraction
Visual Models
Number Sense
Concrete Representation
Two-Digit Numbers
ON Curriculum Aligned