Definition
Count on
Count on means start at a known number and say the numbers that come next.
What it means
Keep the starting number in your head, then move forward through the next numbers. When you use count on for addition, say one new number for each one being added instead of beginning again at 1.
Remember it
Keep the start; every next number is one more step.
Example
To work out 8 + 3, start on 8 and count three forward steps: 9, 10, 11. The result is 11.
Watch for
For 7 + 4, saying 7, 8, 9, 10 uses 7 as a counted step and stops at 10. The four forward counts are 8, 9, 10, 11.
Common mix-up
In everyday English, “count on me” means rely on me. The maths phrase is about continuing a number sequence.
Exact meaning
To count on is to continue a counting sequence forward from a known starting number, usually moving on by one for each count. In addition, the starting number is already known and is not the first added step.