Reading and writing decimals to thousandths
In 5th grade, children learn to read decimals to thousandths by their place names; to write them in digits; and to break them into expanded form, such as 0.362 = 0.3 + 0.06 + 0.002.
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
A sunflower seed has a mass of fifty-eight thousandths of a gram. How is that written as a decimal?
- 0.58
- 0.058
- 58,000
Why this matters
Reading a decimal by its place names is how your child comes to see what the digits after the decimal point really mean. Hearing 0.375 as "three hundred seventy-five thousandths" tells them it is part of one whole. That sense carries into rounding and decimal arithmetic later this year, and into percentages in 6th grade. You'll spot it on gas station signs, race times, and kitchen scales.
Once your child can read a decimal by its place names, the next step is comparing decimals to thousandths, which puts those names to work.
Where kids can get stuck
- Reading 4.26 as "four point twenty-six" and missing that the digits after the decimal point mean 26 hundredths.
- Leaving out a zero when writing from words, so "five and twelve thousandths" becomes 5.12 instead of 5.012.
- Treating every digit as tenths in expanded form, writing 0.642 as 0.6 + 0.4 + 0.2 instead of 0.6 + 0.04 + 0.002.
How you can help
- Read gas prices aloud together on a drive. A price of $3.459 means 3 dollars and 459 thousandths of a dollar, so ask your child which digit is in the thousandths place and what it is worth.
- Say a decimal at dinner, like "seven and six hundredths," and have your child write it down as 7.06. Then switch, so they say one and you write it. A mistake on either side makes good conversation.
- Look up a favorite player's batting average, like .312, and have your child read it as three hundred twelve thousandths. Then ask them to break it into 3 tenths, 1 hundredth, and 2 thousandths.
Bobby's Math Club offers free practice that grows with your child.
Questions parents ask
Why is my child learning to read decimals using place names?
Saying "three hundred forty-seven thousandths" instead of "point three four seven" connects the number to its meaning. Your child hears that the digits describe thousandths of a whole. That understanding helps with rounding and with adding and subtracting decimals later this year. Both ways of reading are used in daily life, and knowing the place value version first helps the shortcut make sense.
What is expanded form for decimals?
Expanded form writes a number as the sum of what each digit is worth. For 3.528, that is 3 + 0.5 + 0.02 + 0.008. Your child may also see it written with fractions, such as 5 × (1/10) for the 5 tenths. Every version says the same thing: the 5 is worth five tenths, the 2 is worth two hundredths, and the 8 is worth eight thousandths.
How do you say a decimal like 2.045 out loud?
Say the whole number, then "and" for the decimal point, then the digits after it as one number, followed by the name of the last place. So 2.045 is "two and forty-five thousandths." The name comes from the 5, which sits in the thousandths place. The "and" marks the decimal point, so it is best saved for that spot: 245 is "two hundred forty-five," with no "and."
Make learning math fun
Bobby's Math Club turns 5th grade math practice into something fun to do together.
- Unlimited free practice
- Questions matched to your child’s level, a few minutes a day
- 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.
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Join the clubNote for teachers: This skill is covered by Common Core math standard 5.NBT.A.3: “Read, write, and compare decimals to thousandths. a. Read and write decimals to thousandths using base-ten numerals, number names, and expanded form, e.g., 347.392 = 3 × 100 + 4 × 10 + 7 × 1 + 3 × (1/10) + 9 × (1/100) + 2 × (1/1000). b. Compare two decimals to thousandths based on meanings of the digits in each place, using >, =, and < symbols to record the results of comparisons.” Learn how Bobby's Math Club can help your students grow. (Common Core 5.NBT.3)