Illustrative Mathematics Grade 2, Unit 5: Numbers to 1000
In this unit, your child builds an understanding of numbers up to 1,000. They use base-ten blocks to see hundreds, tens, and ones, place numbers on a number line, and skip-count by 5s, 10s, and 100s. They write numbers in expanded form and compare them using >, =, and <. Geometry, time, and money come next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 5?
- Using base-ten blocks to show that 1 hundred is 10 tens and that a number like 640 is 6 hundreds and 4 tens. Learn more: Hundreds, tens, and ones in numbers like 706
- Counting and skip-counting by 5s, 10s, and 100s within 1,000, including on a number line. Learn more about counting within 1,000: Counting within 1,000 · Learn more about skip-counting by 5s, 10s, and 100s
- Writing three-digit numbers as numerals, as number names, and in expanded form, and matching the forms. Learn more: Reading and writing numbers to 1,000
- Comparing three-digit numbers on a number line and with place value, using >, =, and <. Learn more: Comparing three-digit numbers with >, =, and <
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
How many hundreds are in 300?
- 3
- 30
- 300
How you can help
- Look at prices or house numbers on a walk and ask whether each one is closer to 100, 500, or 1,000.
- Count by 5s, then 10s, then 100s at bedtime, and stop at a surprise number like 635 to say it in hundreds, tens, and ones.
- Write numbers that sound alike, like 416 and 461, and ask your child which is greater and how they know.
Where kids can get stuck
- Writing six hundred forty as 60040, writing each part the way it sounds.
- Jumping from 590 to 5100 instead of 600 when counting by 10s.
- Comparing the last digits first, so 409 seems more than 490.
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
- base-ten blocks
- Blocks for ones, tens, and hundreds that help children build and see numbers.
- hundred
- Ten tens, or 100. In 482, the 4 means 4 hundreds.
- place value
- The value a digit has because of its spot in a number: ones, tens, or hundreds.
- expanded form
- A number written as the sum of its parts, like 400 + 30 + 6 for 436.
- number name
- A number written in words, like four hundred thirty-six.
- skip-count
- Counting by a number other than one, like 5, 10, 15, 20.
- greater than
- More than. The symbol > means greater than, as in 52 > 25.
- less than
- Fewer than. The symbol < means less than, as in 25 < 52.
Ready to build your child’s confidence with numbers up to 1,000?
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 Illustrative Mathematics Grade 2 Unit 5 cover?
Illustrative Mathematics Grade 2 Unit 5 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
- 2.NBT.A.1: Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones.
- 2.NBT.A.2: Count within 1000; skip-count by 5s, 10s, and 100s.
- 2.NBT.A.3: Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.
- 2.NBT.A.4: Compare two three-digit numbers.
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.