Multiplying Two- and
Three- Digit Numbers
by a One- Digit Number
Step 1
Think about 3
groups of 24.
24
3x
24
3x
Step 2
Multiply the
ones.
Think:
4 x 3 = 12
24
3x
Step 3
Regroup 12
ones as 1
ten and 2
ones. Write
down the
ones. Carry
the tens.
24
3x
2
1
Step 4
Then multiply
the bottom
ones times
the tens.
Add in the
one ten you
carried over.
Think:
6 tens + 1 ten
= 7 tens
7
24
3x
2
1
Step 5
Your final
answer is 72.
7
24
3x
2
1
Let’s try another problem!
Step 1
Think about 5 groups of 45.
45
5x
45
5x
Step 2
Multiply the
ones.
Think:
5 x 5 = 25
45
5x
Step 3
Regroup 25
ones as 2
tens and 5
ones. Write
down the
ones. Carry
the tens.
45
5x
5
2
Step 4
Then multiply
the bottom
ones times
the tens.
Add in the
two ten you
carried over.
Think:
20 tens +
2 tens = 22
45
5x
5
2
22
Step 5
Your final
answer is
225.
Let’s try a harder problem!
45
5x
5
2
22
Step 1
Think about 4 groups of 364.
64
4x
3
Step 2
Multiply the
ones.
Think:
4 x 4 = 16
64
4x
364
4x
3
Step 3
Regroup 16
ones as 1
ten and 6
ones. Write
down the
ones. Carry
the tens.
6
1
64
4x
3
Step 4
Then multiply
the bottom
ones times
the tens.
Add in the
one ten you
carried over.
Think:
24 tens + 1 ten
= 25 tens
6
64
4x
3
1
Step 5
Regroup 25 tens
as two hundreds
and five tens.
Write down the
tens. Carry the
hundreds.
64
4x
3
6
1
5
2
Step 6
Then multiply
the bottom
ones times
the hundreds.
Add in the
two hundreds
you carried
over.
Think:
12 hundreds + 2
hundreds = 14
6
64
4x
3
12
5
Step 7
Your final
answer is
1,456. 6
64
4x
3
12
51,4
Now try some on your own!

Multiplying by two-and_three digit