Reading and writing numbers up to a million
In 4th grade, children learn to read and write whole numbers up to a million in digits, such as 305,120; in words; and in expanded form.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
Try these with your child
These are real questions from our 4th 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 number has 6,000 in its expanded form?
- 26,418
- 62,418
- 28,164
Why this matters
Your child is surrounded by big numbers, from the miles on the car to the seats in a stadium, and reading them with confidence makes the world a little easier to understand. Reading and writing them correctly comes before rounding, adding, or multiplying them, which your child does this year. In 5th grade, the same idea stretches past the decimal point, to tenths, hundredths, and thousandths.
With big numbers read and written correctly, your child is ready for comparing numbers up to a million.
Where kids can get stuck
- Writing "forty thousand six" as 4,006 or 400,006, unsure how many zeros fill the empty places.
- Leaving out a place in expanded form, writing 30,405 as 30,000 + 4 + 5 instead of 30,000 + 400 + 5.
- Reading 245,318 as "two hundred forty-five, three hundred eighteen," leaving out the word thousand.
How you can help
- Read big numbers aloud from real life, such as the car’s odometer or the population on a town sign. Have your child say the number, then write it in expanded form on a scrap of paper.
- Take turns calling out numbers in the car. Say one, such as "six hundred eight thousand, forty," for your child to write in digits, 608,040, then swap so your child says one for you.
- Write a number in expanded form on a napkin, such as 200,000 + 6,000 + 40 + 8, and ask your child to write it as one number, 206,048, and read it aloud.
For more, Bobby's Math Club has free practice at your child’s level.
Questions parents ask
Why is my child learning to write numbers in expanded form?
Expanded form shows what each digit is worth. Writing 7,206 as 7,000 + 200 + 6 makes it clear that the 2 means 200 and that the tens place is empty. This helps your child read large numbers correctly, and later add, subtract, and multiply them by place. It is a way to see inside a number rather than an extra chore.
Where do the commas go in a big number?
Count three digits from the right and put a comma there. Each comma marks a new group, so the digits before it tell how many thousands. To read 482,615, your child reads the group before the comma, says "thousand," then reads the rest: four hundred eighty-two thousand, six hundred fifteen. Saying the number in two chunks like this makes even six digits manageable.
Should my child say "and" when reading big numbers?
In math class, children are usually taught to save "and" for the decimal point, as in 3.5, "three and five tenths." So 305 is read "three hundred five," and 2,050 is read "two thousand fifty." Plenty of adults say "three hundred and five" in everyday talk, and that’s fine at home. It helps to know why your child’s teacher may gently correct it.
Make learning math fun
Bobby's Math Club turns 4th grade math practice into something fun to do together.
- Unlimited practice, completely free
- A few minutes a day, at just the right level
- Hints when they are stuck, and a celebration when it clicks
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 4th 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 4.NBT.A.2: “Read and write multi-digit whole numbers using base-ten numerals, number names, and expanded form. Compare two multi-digit numbers 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 4.NBT.2)