5th Grade · Operations & Algebraic Thinking
5.OA.A.2: Turn words into calculations like (5 + 7) × 3, and explain them
5.OA.A.2 is a 5th grade Common Core math standard in Operations & Algebraic Thinking. 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
Write simple expressions that record calculations with numbers, and interpret numerical expressions without evaluating them. For example, express the calculation "add 8 and 7, then multiply by 2" as 2 × (8 + 7). Recognize that 3 × (18932 + 921) is three times as large as 18932 + 921, without having to calculate the indicated sum or product.
In plain words
Turn words into calculations like (5 + 7) × 3, and explain them.
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
Which words match (40 - 8) ÷ 4?
- Subtract 8 from 40, then divide 4 by the answer.
- Subtract 8 from 40, then divide by 4.
- Divide 8 by 4, then take the answer from 40.
Where students can get stuck
- Writing the numbers in the order they appear, so "multiply by 3 the sum of 5 and 7" becomes 3 × 5 + 7.
- Calculating before describing, so they work out 5 × (14 + 9) = 115 instead of saying it is five times 14 + 9.
- Leaving out the parentheses, so "add 4 and 6, then double it" becomes 4 + 6 × 2 = 16 instead of 20.
Effective teaching strategies
- Have students write an expression for “add 4 and 6, then double it” before calculating, and compare it with 4 + 6 × 2 to see why the parentheses are needed.
- Ask students to describe 5 × (14 + 9) in words, such as “five times the sum of 14 and 9,” without finding the product.
- Give students 3 × (5 + 7) and (3 × 5) + 7, and ask which one is three times the sum of 5 and 7, without calculating either one.
Units that teach this standard
Find where 5.OA.A.2 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
Math Expressions
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Turning words into number sentences for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice problem solving 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.