Math Expressions Grade 4, Unit 1: Place Value and Multidigit Addition and Subtraction
In this unit, your child explores how our place-value system works with numbers up to a million: reading and writing them in different forms, comparing them, and seeing that each place is ten times the one to its right. They then add and subtract multidigit numbers. Multiplying whole numbers, which leans on the same place-value ideas, comes next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 1?
- Recognizing that moving a digit one place to the left makes it worth ten times as much, so 50 × 10 = 500. Learn more: Why each place is worth ten times the next
- Reading and writing multidigit numbers in digits, word form, and expanded form, and comparing them using greater than and less than. Learn more about reading and writing numbers up to a million: Reading and writing numbers up to a million · Learn more about comparing numbers up to a million
- Adding and subtracting multidigit numbers by lining up place values and regrouping, including subtracting from numbers like 5,000. Learn more about adding numbers up to a million: Adding numbers up to a million · Learn more about subtracting numbers up to a million
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
Compare 40 thousands and 4 ten thousands. Which is true?
- 4 ten thousands is more
- They are equal
- 40 thousands is more
How you can help
- Play "what is it worth?": write a number like 7,777 and ask your child what each 7 is worth and how it compares with the 7 to its right.
- Read the number of people at a ball game or the height of a mountain aloud, and ask your child to write it in words and in expanded form.
- Subtract to compare real numbers, like the pages in two thick books, and ask your child to check the difference by adding it back.
Where kids can get stuck
- Seeing 500 as 450 more than 50, but not as ten times 50.
- Leaving out a place in expanded form, writing 30,405 as 30,000 + 4 + 5 instead of 30,000 + 400 + 5.
- Getting stuck subtracting across zeros in 5,000 − 2,346, forgetting to regroup the thousands and then the hundreds.
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
- place value
- The value a digit has because of where it sits in a number.
- digit
- Any one of the ten symbols 0 through 9 that we use to write numbers.
- ten times
- Ten groups of the same amount; each place is worth ten times the place to its right.
- expanded form
- A number written as the sum of what each digit is worth, like 4,000 + 300 + 20 + 5.
- word form
- A number written in words, such as six thousand, forty.
- greater than
- Larger than another number, shown with the sign >, as in 12,400 > 9,850.
- regroup
- To trade 10 of one place for 1 of the next, like 10 ones for 1 ten.
- difference
- The answer to a subtraction problem.
Ready to build your child’s confidence with numbers up to a million?
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.
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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 Math Expressions Grade 4 Unit 1 cover?
Math Expressions Grade 4 Unit 1 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
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.