Work out number bonds instantly with clear inputs, formula shown and shareable results.
The missing part is the total minus the known part; whole-number ordered pairs number total + 1, and unordered pairs floor(total / 2) + 1. Instant recall of bonds to 10 and 20 is what allows children to add by bridging rather than counting on their fingers.
Missing part
missing = total - known part
How many bonds
ordered pairs = total + 1; unordered pairs = floor(total / 2) + 1
missing = total - known part. The missing part is the total minus the known part; whole-number ordered pairs number total + 1, and unordered pairs floor(total / 2) + 1.
Instant recall of bonds to 10 and 20 is what allows children to add by bridging rather than counting on their fingers.
Enter bond total, one part. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.