Into Math Grade 4, Unit 1: Place Value and Whole Number Addition/Subtraction
In this unit, your child starts fourth grade with big numbers, reading and writing them up to a million, comparing them, and learning that each place is worth ten times the place to its right. They then add and subtract multidigit numbers with the usual written method. That place-value thinking carries straight into the multiplication concepts and strategies that come next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 1?
- Seeing that a digit in one place is worth ten times the same digit in the place to its right, like 3,000 and 300. Learn more: Why each place is worth ten times the next
- Writing numbers up to 1,000,000 in digits, words, and expanded form, and comparing two numbers place by place with >, <, and =. 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 whole numbers with the written method in columns, regrouping whenever a column needs it. 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
- Use dimes and dollars if you have them: 10 dimes make a dollar, so ask your child how many dimes are in $10 and why the answer is 100.
- Compare two big numbers you come across, such as the seats in two stadiums or the heights of two mountains, and ask which place decides which is greater.
- Work out how many years apart two events were, such as the year a grandparent was born and this year, subtracting in columns and checking by adding back.
Where kids can get stuck
- Saying the 3 in 3,000 and the 3 in 300 are worth the same, without looking at their places.
- Judging only by the first digit, so 9,850 seems greater than 12,400 even though it has fewer digits.
- Lining numbers up by their left edges instead of by place, so adding 2,375 + 418 puts the 4 under the thousands.
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
- digit
- Any one of the ten symbols 0 through 9 that we use to write numbers.
- place value
- The value a digit has because of where it sits in a number.
- ten times
- Ten groups of the same amount; each place is worth ten times the place to its right.
- period
- A group of three places in a big number, set off by commas, such as the thousands.
- 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.
- regroup
- To trade 10 of one place for 1 of the next, like 10 ones for 1 ten.
- sum
- The answer to an addition problem.
Want to help your child master place value and big numbers?
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 Into Math Grade 4 Unit 1 cover?
Into Math 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.