Number Bonds – Numbers That Fit Together

A number bond shows how a number can be split into two smaller parts – and how those two parts fit back together to make the whole again. For example, 7 can be split into 3 and 4, since 3 + 4 = 7. Number bonds are the essential bridge between everything learned so far in this section and formal addition and subtraction, which begin properly in the Arithmetic Operations section that follows.

The term “number bonds” was popularised by Singapore's national mathematics curriculum, part of an approach often called “Singapore Math” internationally. It spread to classrooms around the world from the 1990s onward, after Singapore's students began consistently ranking among the very best in the world on international maths assessments – and the way the curriculum builds number sense step by step, with number bonds as an early cornerstone, is widely credited as one of the reasons why.

Part, Part, Whole

Real-Life Application

• Splitting a group of friends into two teams that add up to the total.
• Making change: working out how coins combine to a target amount.
• Mental maths: quickly finding “what's missing” without counting from scratch.

Key Takeaways

Practice: Number Bonds