SME
Grade 2 Math · Number & Base Ten
Fluently add and subtract within 100
Use this for “What is 38 + 25? What is 63 − 25?”
Picture
This is an example. Type the numbers from your problem to start.
First number
+
Second number
=
Total
Number sentences
38 + 25 = 63
63 − 25 = 38
Good to know
•
Whole numbers up to 100.
•
Jump by tens, then by ones: 38 + 25 = 38 + 20 + 5.
•
Subtraction undoes addition: 38 + 25 = 63, so 63 − 25 = 38.
Step-by-step
WE KNOW
First number: 38
Second number: 25
FIND
total
Step 1 · Find total
38 + 25 = ?
On the number line, jump by tens, then by ones.
1
3
8
+
2
5
6
3
38 + 20 = 58
58 + 2 = 60
60 + 3 = 63
Total: 63
Check
Put the numbers back in. Both sides should match.
38 + 25 = 63 ✓
63 − 25 = 38 ✓
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.
Refresh
More problem types
Addition and subtraction facts to 20
Use this for “Find the value of each expression: 8 + 7, 12 − 5.”
Solve addition and subtraction word problems
Use this for “Leo adds 16 books to a cart. Now there are 43. How many were there before?” and “How many did he add?”
Add up to four two-digit numbers
Use this for “Find the value of 15 + 15 + 20 + 5.”
Solve compare problems
Use this for “28 in the gym, 65 in the library. How many more are in the library?”
Compare, then add
Use this for “Ben has 8 more than Ana. How many in all?”
Two-step problems: add, then subtract
Use this for two-step problems: some come, then some go.
Two-step problems: subtract, then add
Use this for two-step problems: some go, then some come.
Two-step problems: subtract, then subtract
Use this for two-step problems where some go, twice.
Two-step problems: add, then add
Use this for two-step problems where some come, twice.