Eureka Math Grade 1, Module 6: Addition and Subtraction to 100 and Word Problems
In this unit, first graders work with numbers to 100 and beyond: counting to 120, adding two-digit numbers, finding 10 more and 10 less, and subtracting tens. They solve story problems and read data, or information, from simple charts. It ends the year, putting together last unit's time and shapes with the place value they have built all year.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Module 6?
- Solving word problems within 20 of every kind, including ones where the start or the change is the missing number. Learn more: Adding and subtracting story problems within 20
- Counting, reading, and writing numbers all the way to 120, including tricky ones like 104 and 110. Learn more: Counting, reading, and writing numbers to 120
- Using tens and ones to name any number to 100, like 85 as 8 tens and 5 ones. Learn more: Tens and ones in two-digit numbers
- Adding within 100, like 47 + 8 or 47 + 30, by adding tens and ones and making a new ten. Learn more: Adding two-digit numbers within 100
- Finding 10 more or 10 less than any two-digit number, even near the ends, like 10 less than 15. Learn more: 10 more or 10 less in your head
- Subtracting multiples of ten within 100, like 90 - 60, and checking with addition. Learn more: Subtracting tens, like 70 - 30
- Reading simple charts and tallies to answer how many in all and how many more or fewer. Learn more: Sorting, tallying, and reading simple charts
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
I had some toy cars. My friend gave me 3 more cars. Now I have 8 cars in total. How many toy cars did I have at first?
- 3
- 5
- 8
How you can help
- Add a price to a multiple of ten at the store, like 47 cents and 30 cents, or find what's left from 90 cents after spending 60. Let your child explain their steps.
- Count by ones on a walk, crossing 100: 98, 99, 100, 101. Then ask for 10 more and 10 less than a house number you pass.
- Keep a tally for a week of something your family does, like books read at bedtime, and ask how many in all and how many more on the busiest day.
Where kids can get stuck
- Writing 47 + 8 as 415, keeping all 15 ones instead of making a new ten.
- Getting stuck on 10 less than 15 or 10 more than 92, where the number of digits changes.
- Writing one hundred four as 1004, putting 100 and 4 side by side.
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
- tens
- Groups of ten. In 34, there are 3 tens.
- ones
- Single things not in a group of ten. In 34, there are 4 ones.
- hundred
- Ten tens, written 100.
- sum
- The answer when you add, like 7 in 3 + 4 = 7.
- difference
- The answer when you subtract, like 2 in 9 - 7 = 2.
- 10 more
- The number you get by adding one ten, like 46 to 56.
- 10 less
- The number you get by taking away one ten, like 46 to 36.
- data
- Information collected to answer a question, like everyone's favorite fruit.
- tally mark
- A line drawn to count one thing; every fifth line crosses four.
Ready to build your child’s confidence with numbers to 100?
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 Eureka Math Grade 1 Module 6 cover?
Eureka Math Grade 1 Module 6 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
- 1.OA.A.1: Use addition and subtraction within 20 to solve word problems.
- 1.NBT.A.1: Count to 120, starting at any number.
- 1.NBT.B.2: Understand that the two digits of a two-digit number represent amounts of tens and ones.
- 1.NBT.C.4: Add within 100.
- 1.NBT.C.5: Given a two-digit number, mentally find 10 more or 10 less.
- 1.NBT.C.6: Subtract multiples of 10 in the range 10-90.
- 1.MD.C.4: Organize, represent, and interpret data with up to three categories.
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.