Turning words into number sentences
In 5th grade, children learn to turn words like "add 5 and 7, then triple it" into number expressions, and to read what an expression means before calculating.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
Try these with your child
These are real questions from our 5th grade practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
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.
Why this matters
Being able to move between words and symbols is a big step toward algebra for your child. In 6th grade they will write expressions with letters, like 4 × (n + 2) for four friends each paying for a ticket and a snack. A child who already sees that 3 × (250 + 75) is three times something can check answers by sense, not only by arithmetic.
Where kids 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.
How you can help
- Describe a family purchase out loud, like three kids each getting a $4 sandwich and a $1 drink, and ask your child to write it as one expression, 3 × (4 + 1), before working out the total.
- Write two expressions on a sticky note, such as 6 × (20 + 3) and 20 + 3, and ask your child how they compare without calculating. Listen for "the first is six times the second."
- Play a reverse game at bedtime: you say an expression, like (10 − 4) × 2, and your child tells you a short story that matches it, such as having 10 cookies, eating 4, then doubling the rest.
If it’s helpful, you can sign up for free, adaptive practice in Bobby's Math Club.
Questions parents ask
Why is my child learning to write expressions this way?
Writing an expression slows the thinking down so your child can see the plan before doing the arithmetic. Teachers ask children to explain an expression without solving it because it shows they understand how the parts connect. A child who knows 4 × (6 + 2) means four groups of eight can catch their own mistakes. That kind of reasoning is what algebra builds on in the next few years.
Why does the teacher say not to solve the expression?
Some questions ask your child to interpret, not evaluate. For example, "How does 2 × (348 + 19) compare with 348 + 19?" The answer is that it is twice as large, and finding the actual numbers would miss the point. The goal is to notice structure. Adults do this all the time, such as knowing that two of the same order costs double without adding up the receipt.
What if my child gets the right answer but writes the expression wrong?
That is common, and worth gently addressing. Many children do the steps correctly in their heads but write 5 + 7 × 3 when they meant (5 + 7) × 3. Ask them to read their written expression back exactly as it stands and work it out. When the written version gives a different answer than they expected, they usually see why the parentheses matter.
Make learning math fun
Bobby's Math Club turns 5th grade math practice into something fun to do together.
- Unlimited free practice
- A few minutes a day, at just the right level
- You see their progress and what to work on next
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.
Ready to watch your child’s confidence grow?
Your 5th grade child can start today with free, unlimited practice that grows with them.
Join the clubNote for teachers: This skill is covered by Common Core math standard 5.OA.A.2: “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.” Learn how Bobby's Math Club can help your students grow. (Common Core 5.OA.2)