Eureka Math² Grade 4, Module 5: Operations with Fractions
In this unit, your child adds and subtracts fractions and mixed numbers with like denominators, multiplies a fraction by a whole number, and writes tenths and hundredths as decimals they can compare. Line plots of measurements in halves, fourths, and eighths tie it together. It builds on fraction equivalence and leads into angles, shapes, and measurement.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Module 5?
- Adding and subtracting mixed numbers by breaking them apart, like 2 3/8 + 1 6/8 = 3 9/8 = 4 1/8. Learn more: Adding and subtracting fractions and mixed numbers
- Multiplying a whole number by a unit fraction and by other fractions, like 4 × 1/5 and 4 × 3/5. Learn more: Multiplying a fraction by a whole number
- Writing decimal fractions in decimal form, like 0.4 and 0.04, and naming the place of each digit. Learn more: Writing fractions as decimals, like 0.62
- Comparing decimals like 0.4 and 0.38 with >, =, and <, and explaining with tenths and hundredths. Learn more: Comparing decimals like 0.09 and 0.1
- Making line plots of lengths in eighths of an inch, and answering questions like the difference between the longest and shortest. Learn more: Charting measurements in halves, fourths, and eighths
Sample questions to try together
These are real questions from our 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 sum is equal to 4/5?
- 1/5 + 1/5 + 1/5
- 1/4 + 1/4 + 1/4 + 1/4
- 1/5 + 1/5 + 1/5 + 1/5
How you can help
- Measure leaves or toy cars to the nearest eighth of an inch. Have your child draw a line plot with an X for each length and find the longest minus the shortest.
- Track your child's height on a door frame to the nearest half inch. Ask how much they grew between two dates, subtracting the mixed numbers together.
- Draw a number line from 0 to 1 marked in tenths. Have your child place 0.3, 0.25, and 0.7 on it and say which is largest.
Where kids can get stuck
- Spacing 1/8, 1/4, and 1/2 as equal steps apart on a line plot's number line.
- Adding the fraction values when the question asks how many, or counting Xs when it asks for a total length.
- Thinking a decimal with more digits is bigger, so 0.38 seems greater than 0.4.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- mixed number
- A whole number and a fraction together, like 2 1/4.
- unit fraction
- A fraction with 1 as its numerator, like 1/4 or 1/8.
- decompose
- To break a number or fraction into parts, like 3/4 = 1/4 + 1/4 + 1/4.
- decimal
- A number written with a decimal point, like 0.62, to show parts of a whole.
- hundredths place
- The second place to the right of the decimal point.
- line plot
- A number line with an X above it for each measurement in a set of data.
- data
- Information that has been collected, like a set of measurements.
Want to help your child master fraction operations?
In Bobby's Math Club, your child practices these skills 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.
Join the club
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.
Which math standards does Eureka Math² Grade 4 Module 5 cover?
Eureka Math² Grade 4 Module 5 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
- 4.NF.B.3: Add and subtract fractions with the same denominator, like 5/12 + 6/12.
- 4.NF.B.4: Multiply a fraction by a whole number, like 2 × 3/4.
- 4.NF.C.6: Write tenths and hundredths as decimals, like 4/10 = 0.4.
- 4.NF.C.7: Compare decimals to hundredths, like 0.09 and 0.1.
- 4.MD.B.4: Read line plots marked in fractions, like 1/4 and 1/8 inch.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.