Subtract two-digit numbers and break a ten when needed.
Subtract Within 100 helps second graders subtract tens and ones, and break a ten into 10 ones when they need more ones. Kids also solve take-away and how-many-more stories, so they know when to subtract, not just how.
Math course · Grade 2
Subtract Within 100 · Learning goals
Subtract tens and ones, break a ten into 10 ones when you need more ones, and solve take-away and how-many-more stories.
Why it matters
Breaking a ten into ones shows kids why borrowing works, which prevents common subtraction mistakes.
Knowing when a story needs subtraction is a reasoning skill that matters as much as getting the answer.
Subtracting tens first, then ones, helps kids solve problems in their heads at the store or in games.
Inside Subtract Within 100
A short read-aloud lesson first, then hands-on games and a quiz to lock it in.
Step 1 · Lesson
A short read-aloud lesson in 4 steps, with pictures and worked examples.
Step 2 · Game
Subtract the tens, then the ones. (8 problems)
Step 3 · Game
Not enough ones? Break a ten! (8 problems)
Step 4 · Game
What number makes the equation true? (6 problems)
Step 5 · Game
Read and listen, then subtract. (6 problems)
Lesson preview
This is the real lesson text your child hears, read aloud by a friendly voice.
To subtract, take away the tens and take away the ones. 58 − 23: 5 tens − 2 tens is 3 tens, 8 − 3 is 5 ones. That's 35!
Sometimes there aren't enough ones. For 42 − 17, you can't take 7 from 2. Break a ten into 10 ones!
Now 3 tens and 12 ones. 12 − 7 is 5, and 3 tens − 1 ten is 2 tens. So 42 − 17 = 25!
Check with addition: 25 + 17 = 42. Adding and subtracting are a team!
For parents
Learning sticks best when kids use it in real life. Here are simple ideas from this course.
Start with 75 points in a pretend game and lose some points each round. Your child subtracts to find the new score and explains how they did it.
Practice
Real questions from Subtract Within 100. Try them with your child, then tap to see the answer.
Question 1
54
Question 2
35
Question 3
65
The full course has 28 questions with instant feedback, stars and rewards. Create a free account to play them all.
Subtract Within 100 · Questions from parents
Subtract Within 100 is a grade 2 math course for kids ages 7–8. That is Year 3 maths in the UK and Year 2 in Australia. It also works well for review in the next grade, or as a challenge for a confident younger learner.
Subtract tens and ones, break a ten into 10 ones when you need more ones, and solve take-away and how-many-more stories. Along the way they practice: Take Away Tens and Ones; Break a Ten; Missing Number; Subtraction Stories.
About 10 minutes in total, split into 4 short levels. Most kids finish it over two or three sessions. Progress is saved, so they can stop any time and pick up where they left off.
Yes. Subtract Within 100 is one of the first 2 courses in Grade 2 Math. Create a free parent account and your child can start right away.
No. Every lesson has a friendly read-aloud voice, questions are read aloud too, and the pictures help kids follow along. Confident readers can turn the voice off.
Yes. SkillBloom is built for homeschooling families. Kids work through lessons, games and quizzes on their own, and the parent dashboard shows what they finished and which skills need more practice. It works on phones, tablets and laptops.
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