Into Math Grade 4, Unit 4: Fractions and Decimals
In this unit, your child takes a big step with fractions: finding equivalent fractions, comparing fractions, adding and subtracting with like denominators, and multiplying a fraction by a whole number. They also connect tenths and hundredths to decimals. It follows division strategies, whose multiplying and dividing help with equivalent fractions, and leads into geometry and measurement.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 4?
- Generating equivalent fractions by multiplying the numerator and denominator by the same number, and showing the match with models. Learn more: Why fractions like 3/4 and 6/8 are equal
- Comparing two fractions with different numerators and denominators by using a common denominator, a common numerator, or 1/2. Learn more: Comparing fractions like 2/3 and 5/6
- Adding and subtracting fractions and mixed numbers with like denominators, and breaking a fraction into a sum of smaller fractions. Learn more: Adding and subtracting fractions and mixed numbers
- Multiplying a fraction by a whole number, as in 5 × 1/4, by putting together groups of unit fractions. Learn more: Multiplying a fraction by a whole number
- Renaming tenths as hundredths, so 6/10 = 60/100, in order to add fractions like 6/10 + 25/100. Learn more: Adding tenths and hundredths together
- Writing tenths and hundredths as decimals, like 3/10 = 0.3 and 8/100 = 0.08, and placing them on a number line. Learn more: Writing fractions as decimals, like 0.62
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
What is the missing number? 4/5 = ?/10
- 4
- 9
- 8
How you can help
- Fold paper strips into halves, fourths, and eighths, and ask your child which folds show that 1/2 = 2/4 = 4/8.
- Measure ingredients for a no-cook snack: if each serving uses 1/4 cup of oats and you make 5 servings, ask how many cups that is in all.
- Talk about money as decimals: a dime is one tenth of a dollar and a penny is one hundredth, so ask your child to write 3 dimes and 4 pennies as a decimal.
Where kids can get stuck
- Adding the same number to the numerator and denominator, so 2/3 seems equal to 4/5.
- Adding tops and bottoms straight across, so 3/10 + 4/100 turns into 7/110, without renaming tenths as hundredths first.
- Thinking bigger numbers make a bigger fraction, so 3/10 seems greater than 2/3.
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
- numerator
- The top number of a fraction, which tells how many equal parts are counted.
- denominator
- The bottom number of a fraction, which tells how many equal parts make the whole.
- equivalent fractions
- Fractions that name the same amount, such as 3/4 and 6/8.
- common denominator
- A denominator two fractions share, such as sixths for 2/3 and 5/6.
- mixed number
- A whole number and a fraction together, such as 2 1/4.
- unit fraction
- A fraction with a numerator of 1, such as 1/4, naming one equal part.
- tenths
- Parts of a whole cut into 10 equal pieces, written like 3/10 or 0.3.
- hundredths
- Parts of a whole cut into 100 equal pieces, written like 45/100 or 0.45.
- decimal
- A number written with a decimal point to show tenths and hundredths, such as 0.45.
Want to help your child master fractions and decimals?
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 Into Math Grade 4 Unit 4 cover?
Into Math Grade 4 Unit 4 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
- 4.NF.A.1: Find equal fractions, like 3/4 = 6/8, by multiplying top and bottom.
- 4.NF.A.2: Compare fractions with different denominators, like 2/3 and 5/6.
- 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.5: Turn tenths into hundredths to add them, like 3/10 + 4/100.
- 4.NF.C.6: Write tenths and hundredths as decimals, like 4/10 = 0.4.
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.