5th Grade · Number & Operations in Base Ten
5.NBT.A.3: Read, write, and compare decimals to thousandths
5.NBT.A.3 is a 5th 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
Read, write, and compare decimals to thousandths. a. Read and write decimals to thousandths using base-ten numerals, number names, and expanded form, e.g., 347.392 = 3 × 100 + 4 × 10 + 7 × 1 + 3 × (1/10) + 9 × (1/100) + 2 × (1/1000). b. Compare two decimals to thousandths based on meanings of the digits in each place, using >, =, and < symbols to record the results of comparisons.
In plain words
Read, write, and compare decimals to thousandths.
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 6
A sunflower seed has a mass of fifty-eight thousandths of a gram. How is that written as a decimal?
- 0.58
- 0.058
- 58,000
Where students can get stuck
Read and write decimals to thousandths.
- Reading 4.26 as "four point twenty-six" and missing that the digits after the decimal point mean 26 hundredths.
- Leaving out a zero when writing from words, so "five and twelve thousandths" becomes 5.12 instead of 5.012.
- Treating every digit as tenths in expanded form, writing 0.642 as 0.6 + 0.4 + 0.2 instead of 0.6 + 0.04 + 0.002.
Compare decimals to thousandths.
- Thinking the decimal with more digits is larger, so 0.125 seems greater than 0.5 because 125 is greater than 5.
- Deciding the shorter decimal is always larger, so 0.3 seems greater than 0.35 because tenths are bigger than hundredths.
- Missing that zeros at the end change nothing, so they say 0.4 and 0.400 are different instead of equal.
Effective teaching strategies
- Write decimals in expanded form with students, such as 0.125 as 1 tenth + 2 hundredths + 5 thousandths, and have them read each place aloud.
- Ask students to compare 0.125 and 0.5 by renaming both in thousandths, 125 and 500, and then compare 0.3 with 0.35 the same way.
- Model reading 4.26 as “four and twenty-six hundredths,” and have students shade it on hundredths grids to see why the digits after the point name hundredths.
Units that teach this standard
Find where 5.NBT.A.3 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
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
Each skill has its own guide for families, with a plain-language look at the skill, 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.