Why number bonds matter
Knowing that 8 and 2 make 10 is the key to adding 8 + 5 in your head: 8 + 2 + 3. Bonds and fact families make that connection visible.Provincial curriculum links
- BC KWays to make 5, and breaking apart and rebuilding numbers to 10 with part-part-whole thinking.
- BC Grade 1Ways to make 10, breaking 20 into parts, and seeing that addition and subtraction are related.
- ON Grade 2Adjusting pairs of addition and subtraction statements so they are equal.
- BC Grade 3Most students can recall addition facts to 20 by the end of the year.
BC’s curriculum uses part-part-whole language from Kindergarten, so the number bond diagram will already feel familiar to BC students. In BC, bonds to 5 suit Kindergarten, bonds to 10 suit Grade 1, and bonds to 20 carry through Grades 2 and 3 as facts become fluent.
Fact family triangles show how addition and subtraction undo each other, which BC names in Grade 1 and Ontario builds on in its Algebra strand when students make two number statements equal.
Summarized in our own words from the BC Mathematics curriculum (K–3) and Ontario’s overview of The Ontario Curriculum, Grades 1–8: Mathematics (2020).
