SME
Grade 5 Math · Number & Base Ten
Fluently multiply multi-digit whole numbers
Use this for “Multiply: 234 × 56” with the standard algorithm.
Diagram
234 × 56: 10,000 + 1,500 + 200 + 1,200 + 180 + 24 = 13,104.
This is an example. Type your own values to start a new problem.
First factor
×
Second factor
=
Product
Formulas
234 × 56 = 13,104
First factor × second factor = product
Assumptions
•
Multiply by the ones digit of the second factor. Carries go above.
•
Then by the tens digit: write a 0 in the ones place first.
•
Add the two rows. Check with an estimate.
•
First factor to 99,999, second factor 2 to 99. A one-digit second factor needs one row.
Step-by-step
WE KNOW
First factor: 234
Second factor: 56
FIND
product
Step 1 · Find product
234 × 56 = ?
First factor × second factor = product
A row for the ones digit, a row for the tens digit (a 0 first), then add the rows.
Ones digit: 234 × 6 = 1,404
Tens digit: 234 × 50 = 11,700
Add the rows: 1,404 + 11,700 = 13,104
1
2
2
2
2
3
4
×
5
6
1
4
0
4
+
1
1
7
0
0
1
3
1
0
4
Product = 13,104 (about 200 × 60 = 12,000, so 13,104 is reasonable)
Check
Put the numbers back in. Both sides should match.
234 × 56 = 13,104 ✓
Topic check
See what you know: 5 questions on this topic
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