1.NBT.1: Count, Read and Write to 120
Also written as 1.NBT.A.1 and CCSS.MATH.CONTENT.1.NBT.A.1 · Cluster: Extend the counting sequence.
The Official Wording
Count to 120, starting at any number less than 120. In this range, read and write numerals and represent a number of objects with a written numeral.
Common Core State Standards, Grade 1, Number & Operations in Base Ten · Read it at the source · Checked October 14, 2026
What 1.NBT.1 Means in Plain English
First graders count forward from any number up to 120, read and write those numerals, and write the number that matches a pile of objects. A child starting at 96 says 97, 98, 99, 100, 101 and writes one hundred one as 101, not 1001.
The new ground is past 100, where the pattern from 1 to 20 repeats with a hundred in front, and writing those three-digit numbers. In 2nd grade the count runs to 1,000 with skip-counting by 5s, 10s and 100s (2.NBT.2).
1.NBT.1 I Can Statements
- I can count to 120 starting at any number.
- I can read and write numbers up to 120.
- I can write the number that tells how many objects.
1.NBT.1 Worked Example
A count that starts in the middle and crosses 100, the stretch where 1st graders most often lose the pattern.
The class has already counted 96 straws for the 100th-day tower. Ana adds 16 more, one at a time. Count on from 96 and write how many straws there are.
- Start at 96, not at 1. Say the number, then count on as each straw goes in.96, 97, 98, 99
- After 99 the next number is one hundred.100
- Past 100 the count sounds like the start of the chart again, with one hundred in front.101, 102, 103, ... 109
- After 109 comes one hundred ten, just like 9 to 10. Ana is down to her last straws.110, 111, 112
- Write the last number said. One hundred twelve is a hundred, a ten and 2 ones, so it has three digits.112, not 10012
Check it: Count the straws Ana added on fingers as the numbers go by: 97 to 112 is 16 counts, the number she put in.
Common Mistakes with 1.NBT.1
Writing numbers the way they sound
One hundred twelve written as 10012
Try this: Lay a hundreds chart beside a 101 to 120 strip and have students copy numbers from the strip, saying each one aloud.
Stalling after 100
“98, 99, 100, 200”
Try this: Count the 100 to 120 stretch every morning, pointing to each number, until 101, 102 sounds as ordinary as 1, 2.
Starting from 1 every time
Asked to count on from 87, quietly counts 1 to 87 first
Try this: Give a start card, say 87, and have the student read it aloud, then count on three numbers and stop.
Where 1.NBT.1 Fits
Practice 1.NBT.1
Quick Check
- What number comes after 109?
- Count on from 117. What are the next three numbers?
- Write the number one hundred four.