Counting on is a simple addition strategy that helps young learners add without starting at 1 every time. The idea is to hold the bigger number in your head, then count up the smaller number using fingers, dots, or steps. This makes addition faster and helps children see numbers as amounts they can build on.
It is an important early skill for mental math.
Key Facts
- Counting on means starting with one number and saying the next numbers in order.
- Use the bigger number first because it saves counting steps.
- For 7 + 3, think 7, then count 8, 9, 10, so 7 + 3 = 10.
- The number in your head is the starting number, not the answer yet.
- The number on your fingers tells how many counts to make.
- Addition can be done in either order: 3 + 7 = 7 + 3.
Vocabulary
- Counting on
- Counting on is an addition strategy where you start at a number and count forward.
- Bigger number
- The bigger number is the number with the greater value in an addition problem.
- Addend
- An addend is a number that is added to another number.
- Sum
- The sum is the answer to an addition problem.
- Mental math
- Mental math is solving a math problem in your head without writing every step.
Common Mistakes to Avoid
- Starting at 1, because this ignores the shortcut and makes the problem take longer.
- Counting the starting number as the first finger count, because the starting number is already being held in your head.
- Using the smaller number as the starting number, because it may make you count more steps than needed.
- Stopping one count too early, because each finger or count must match one added amount.
Practice Questions
- 1 Use counting on to solve 8 + 2. Write the numbers you say after 8.
- 2 Use counting on to solve 5 + 4. Start with the bigger number.
- 3 Jada solves 2 + 9 by starting at 1 and counting all the objects. Explain a faster way she can solve it using counting on.