4th Grade · Operations & Algebraic Thinking
4.OA.A.2: Solve "times as many" word problems by multiplying or dividing
4.OA.A.2 is a 4th 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
Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.
In plain words
Solve "times as many" word problems by multiplying or dividing.
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
Amara's dad planted 3 times as many bean seeds as Amara. Amara planted 12 seeds. How many seeds did her dad plant?
- 15
- 4
- 36
Where students can get stuck
- Multiplying whenever they see "times," so "18 is 3 times as many as what number?" gets 54 instead of 6.
- Adding instead of multiplying, so "3 times as much as $6" becomes $9 instead of $18.
- Drawing the bar model backwards, with the larger amount as one bar, which points them to the wrong operation.
Effective teaching strategies
- Draw a bar model for each comparison problem, with the smaller amount as one unit and the larger amount as several equal units, before students choose an operation.
- Ask students to write the unknown as a box or letter and say whether it is the larger or the smaller amount, such as 18 = 3 × ? and ? = 3 × 6.
- Give a pair of problems built on the same numbers, such as “3 times as many as 6” and “18 is 3 times as many as what number,” and ask why one multiplies and the other divides.
Units that teach this standard
Find where 4.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
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 Story problems about "times as many" 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.