Numbers 0–10 can be broken into two parts that combine to make 10. Understanding all the ways to make 10 (like 7 + 3, 6 + 4, 8 + 2) is a foundation for mental math and addition facts. Number bonds show visually how a whole relates to its parts.
Use manipulatives like blocks or counters. Start with familiar pairs (5 + 5, then 6 + 4), then discover others. Practice until students recognize bonds automatically.
You've already practiced addition within 10 and learned number bonds within 5 — so you know what it means to break a small number into two parts and put them back together. Number bonds to 10 extend that same idea to the most important number in our number system: ten. Because we count in groups of ten, knowing all the ways to make 10 is one of the most useful things you can learn in early mathematics.
The key insight is the part-whole relationship: 10 is the whole, and any two numbers that add up to 10 are its parts. There are exactly ten pairs (if you count 0 + 10): 0 + 10, 1 + 9, 2 + 8, 3 + 7, 4 + 6, 5 + 5, 6 + 4, 7 + 3, 8 + 2, 9 + 1. Notice the symmetry — 3 + 7 and 7 + 3 are the same bond, just flipped. Once you know one fact, you automatically know its partner. Number bonds are not just addition facts to memorize; they're a map showing how 10 can be taken apart and put back together in different ways.
Why does this matter? Because 10 is the bridge to bigger numbers. When you need to add 8 + 5, a skilled mathematician thinks: "8 needs 2 more to make 10, and 5 has a 2 to spare — so I'll take 2 from the 5, make 10, and have 3 left over: 10 + 3 = 13." That strategy — "make a ten first" — is one of the most powerful mental math techniques, and it only works if you know your bonds to 10 automatically. Every time you add or subtract larger numbers later, you'll be using these bonds without even thinking about it.
Practice with physical objects first — ten blocks, ten counters, ten fingers. Put 7 on one side and 3 on the other. Now slide one block over: 6 and 4. See how the whole stays the same (10) while the parts change? That's the core idea. When the bonds become automatic — when you can instantly recall that 6's partner is 4, that 9's partner is 1 — you've built a piece of number sense that will support your math learning for years.