➕➖ Addition & Subtraction within 100
Master addition and subtraction of two-digit numbers within 100 using place value understanding, decomposing strategies, and regrouping. Build fluency with mental math, standard algorithms, and problem-solving without always needing concrete materials. **What you'll learn:** - Add and subtract two-digit numbers using place value (tens and ones) - Apply decomposing and regrouping strategies - Solve word problems involving sums and differences to 100 - Use mental math and standard algorithms flexibly
Questions in this quiz
Answers hidden — play to find out.
- Question 1
What is ? Think about breaking it into tens and ones.
- Question 2
When you add 24 + 6, you do not need to regroup because 4 + 6 = 10.
- Question 3
Which number sentence matches the problem: Sarah has 34 stickers and buys 22 more. How many stickers does she have now?
- Question 4
What is using regrouping?
- Question 5
Maya uses mental math: . She thinks 'I have 4 tens and 3 tens, that's 7 tens.' What is her answer?
- Question 6
equals .
- Question 7
A toy box has 42 blocks. Some are taken out, and 19 blocks remain. How many blocks were taken out?
- Question 8
Which decomposition helps you find ?
- Question 9
The number 56 can be written as 5 tens and 6 ones.
- Question 10
What is ?
- Question 11
Tom thinks of a number. He adds 11 and gets 37. What was his starting number?
- Question 12
.
- Question 13
Which number is closest to the sum of ?
- Question 14
Emma has 55 cents. She spends 23 cents. How much money does she have left?
- Question 15
To find , you need to regroup 40 as 3 tens and 10 ones.
- Question 16
What is the difference between 72 and 45?
- Question 17
Which addition uses the strategy of counting on by tens?
- Question 18
.