SME
Grade 3 Math · Problem type
Addition and subtraction word problems within 1,000
Use this for “The library had 526 books. It lent out 248. How many are left?”
Diagram
248 + 278 = 526
This is an example. Type your own values to start a new problem.
Books at the start
−
Books lent out
=
Books left
Formulas
526 − 248 = 278
Books at the start − books lent out = books left
Assumptions
•
Find the whole and the parts. The whole is the books at the start.
•
Missing the whole? Add the parts. Missing a part? Take the other part from the whole.
Step-by-step
WE KNOW
Books at the start: 526
Books lent out: 248
FIND
books left
Step 1 · Find books left
526 − 248 = ?
Books at the start − books lent out = books left
Take the books lent out away from the books at the start.
4
11
16
5
2
6
−
2
4
8
2
7
8
Trade 1 ten for 10 ones: 16 ones
Trade 1 hundred for 10 tens: 11 tens
Ones: 16 − 8 = 8
Tens: 11 − 4 = 7
Hundreds: 4 − 2 = 2
Books left = 278
Check
Put the numbers back in. Both sides should match.
526 − 248 = 278 ✓
Topic check
See what you know: 5 questions on this topic
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