This document discusses number bonds and strategies for addition and subtraction using number bonds. Number bonds show the different combinations of numbers that make up a given number. They help build foundations for efficiently learning addition and subtraction. The document outlines activities and strategies like near-10, doubles, and near-100 that use number bonds to develop number sense and mental math skills before learning formal algorithms.
3. Number Bonds
Number bonds are different combinations
of numbers that make up a given number.
4. Different Types of Bonds
67 - 56 = 11
7 – 1 + 5 x 2 = 16
2+3=5
80 ÷ 10 = 8
7 X 8 = 56
5. Purposes
Number bonds lay a strong foundation for
learning addition and subtraction
efficiently.
Number bonds also enhance mental
computations
6. Activities for Lower Grades
Using the magnets and 10-frame
How many bonds are there to make 10?
7. Use concrete manipulative
Generate different possible ways/ bonds
Move to pictorial stage
8.
9. Extension
What are the different sums that you can get with
different sets of whole numbers?
What can you observe?
What can you observe about the number in the middle?
What can you observe about the sums?
10.
11.
12. Open-ended task (with more than 1 sum)
Generate different possible ways/ bonds
Problem-solving task
17. Addition Strategies using Number
Bonds
Near-100 Strategy
245 + 98
Rewrite 98 as (100-2)
Add 245 + 100 = 345
We add more than we should
345 – 2 = 343
18. Debriefing
The ability to see numbers in different
combinations is developing number
sense/ number concept.
22. Subtraction Strategies using
Number Bonds
Addition bonds for Subtraction
16 – 9
16 is made up of (10 + 6)
Use 10 – 9 = 1
Add 1 to 6 (remaining number in the bond)
1+6=7
24. Subtraction Strategies using
Number Bonds
Near-100 Subtraction Strategy
256 - 97
Rewrite 97 as (100 – 3)
256 – 100 = 156
Subtract more than we should
156 + 3 = 159