What are number bonds?
A number bond is a pair of numbers that add up to 10. There are only five pairs to know, and most people already know them intuitively:
When these five pairs become instant recall, you unlock the bridge through 10 technique — the most widely used mental addition strategy.
Bridging Through 10
When the sum of two numbers exceeds 10, split one number to first reach 10, then add the remainder. This turns a hard single-step addition into two trivial ones.
This works because 10 is the easiest number to add to. Once you're at 10, the remaining addition is trivial — just append the ones digit.
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Doubles and Near-Doubles
Doubles (6+6, 7+7, 8+8) are easy to remember because they're symmetric. Once you know your doubles, near-doubles are just one step away.
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Why these matter
Number bonds and bridging are the micro-skills that underpin every advanced technique. Left-to-right addition, rounding and compensating, and even multiplication all reduce to sequences of small additions. When those small additions are instant, the advanced techniques feel effortless.
This is why Velox starts here: build the foundation, and the speed follows naturally.