What is this skill?
In first grade, children extend counting to 120, starting from any number rather than always from 1. A child might be asked what comes next after 57, 58, 59, or to continue counting from 98. They also learn to read and write the numerals in this range.
The hardest moments are the decade changes, such as 29 to 30, 69 to 70 and especially 99 to 100 and 109 to 110. These are the points where the ones reach 9 and the tens go up by one. Children who see the pattern, rather than memorizing each number, find these transitions much easier.
Why it matters
Counting past 100 shows children that our number system keeps the same pattern forever: the ones go from 0 to 9, then the tens change. That pattern is the foundation of place value, and it is what lets children read, write and compare any number later on.
Counting on from a given number is also a building block for adding and subtracting larger numbers. When a child adds 47 + 3 by counting "48, 49, 50," they are using exactly this skill, including the decade change.
Common mistakes
- Stalling or jumping at the decade changes, for example 39 to 50 or 79 to 90, or saying "twenty-ten" instead of thirty. Practicing the decade numbers on their own, 10, 20, 30 up to 120, helps.
- Counting past 100 as "one hundred, two hundred, three hundred" instead of 101, 102, 103. Point out that after 100 the pattern starts again: one hundred one, one hundred two, just like 1, 2, 3.
- Writing numbers as they sound, such as 1004 for one hundred four. Show that 104 is written with three digits: one hundred, zero tens and four ones.
How to help at home
- Make or print a hundred chart (1 to 100, ten per row) and add two rows for 101 to 120. Point to a number and ask your child to keep counting from there. The rows make the decade pattern visible.
- Count collections of 50 to 120 small things, like pennies or dried beans, by grouping them into piles of ten first and then counting on.
- Play "What comes next?" in the car: you say three numbers in order, such as 87, 88, 89, and your child says the next one. Focus on numbers that cross a decade.
- Count backwards occasionally too, from 110 down to 90. Crossing a decade in reverse is a good test of understanding. It also prepares your child for subtraction.
Worked examples
These are real questions from the Tutorsaurus counting to 120 practice, with the answers worked out.
Example 1
What comes next? 53, 54, 55, …
Answer: 56. After 55 comes 56.
Example 2
What comes next? 88, 89, 90, …
Answer: 91. After 90 comes 91.
Example 3
What comes next? 91, 92, 93, …
Answer: 94. After 93 comes 94.