What this covers
Number Pairs and Fact Families is taught in Grade 2 (age 7 to 8) as a topic to introduce. It sits in the Number strand.
Worked example
Find the missing number to complete the bond to 10: 7 + __ = 10
- Start at 7 and count on to 10: 8, 9, 10.
- Three counts were needed.
- Check: 7 + 3 = 10.
Answer: 3
Difficulty scale
The sheet generator offers five difficulty settings for this topic.
- Pairs summing to 5 using visual tens frames
- Pairs summing to 10 with partial visual support
- Pure symbolic pairs summing to 10
- Pairs summing to 20 involving multiples of 5 or ten plus ones
- Arbitrary pairs summing to 20 with missing addends in any position
Common mistakes
- Subtracting the given addend from the wrong base (e.g., thinking 10 - 4 is 5)
- Confusing the part and the whole in bar or part-whole models
Curriculum links
Indicative matches to Common Core State Standards. Check wording and codes against the official document.
- 2.OA.B.2 Fluently add and subtract within 20 using mental strategies.