4th Grade · Number & Operations - Fractions
4.NF.C.7: Compare decimals to hundredths, like 0.09 and 0.1
4.NF.C.7 is a 4th grade Common Core math standard in Number & Operations - Fractions. 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
Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols >, =, or <, and justify the conclusions, e.g., by using a visual model.
In plain words
Compare decimals to hundredths, like 0.09 and 0.1.
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
Mina's ribbon is 0.8 m long. Jae's ribbon is 0.80 m long. Which sign makes this true? 0.8 ___ 0.80
- <
- >
- =
Where students can get stuck
- Thinking a decimal with more digits is bigger, so 0.25 seems greater than 0.3, as if comparing 25 and 3.
- Swinging to the opposite rule, that the shorter decimal always wins, and then saying 0.4 is greater than 0.45.
- Assuming 0.5 of a small pizza is more than 0.3 of a large one, forgetting the wholes are different sizes.
Effective teaching strategies
- Have students shade 0.3 and 0.25 on 10 by 10 grids and say which is more, since 3 tenths is 30 hundredths and 25 hundredths is less.
- Place 0.4 and 0.45 on a number line from 0.4 to 0.5 split into ten equal steps, so students see 0.45 is past 0.4.
- Ask “of the same whole?” before every comparison, and have students show with two paper strips why 0.5 of a short strip can be less than 0.3 of a long one.
Units that teach this standard
Find where 4.NF.C.7 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
Eureka Math²
i-Ready Classroom Mathematics
Illustrative Mathematics
Math Expressions
Reveal Math
Zearn Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Comparing decimals like 0.09 and 0.1 for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice fractions 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.