1st Grade · Number & Operations in Base Ten
1.NBT.A.1: Count to 120, starting at any number
1.NBT.A.1 is a 1st grade Common Core math standard in Number & Operations in Base Ten. Here’s what it really covers, and how you can help your students learn it.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
The standard
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.
In plain words
Count to 120, starting at any number.
Sample questions from student practice
These questions from Bobby's Math Club are the kinds of questions your students will see. You can try answering them to see what a student might see.
Question 1 of 3
Count by tens: 10, 20, 30, 40, __. What number comes next?
- 51
- 50
- 60
Where students can get stuck
- Stalling at a new ten, saying "68, 69, 60" or "79, 70-10" instead of moving on to 70 or 80.
- Stumbling past 100, counting on as "200, 300" or writing one hundred five as 1005 instead of 105.
- Reversing the digits of teen numbers, writing 61 for sixteen because the word starts with the sound of six.
Effective teaching strategies
- Point along a hundred chart as students count from 68 to 72, pausing at 69 and 70 so they see the tens digit change to 7.
- Build one hundred five with a hundred flat and 5 ones, and have students write it, noticing that the empty tens place needs a 0 so it is 105 and not 1005.
- Make sixteen with one ten rod and 6 ones, make 61 with six ten rods and 1 one, and ask which one matches the word "sixteen" and why.
Units that teach this standard
Find where 1.NBT.A.1 lands in the program you teach. Each unit has a guide written for families. Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence.
Bridges in Mathematics
enVision Mathematics
Eureka Math
Everyday Mathematics
i-Ready Classroom Mathematics
Illustrative Mathematics
Math Expressions
Reveal Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Counting, reading, and writing numbers to 120 for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice place value at home
In Bobby's Math Club, students practice at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free for every family.
See how it works for teachers
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.