M u lt ip ly 2 -d ig i t N u m b e r s

Lesson 10.3

S o lv e u s e a s t r a t e g y c a l le d R e g r o u p in g

• STEP 1Multiply the ones. Put

the tens (3) above the tens place.

3

16x5 0

• STEP 2Multiply the tens, then add

the regrouped 3 to the product.

3

16x 58 0

M u lt ip l ic a t io n S t e p s

H T O

3

5 9

x 4

2 3 6

Step 1: Multiply the ones.4 x 9 = 36 ones. Regroup the 36 ones as 3 tens and 6 ones.

Step 2: Multiply the tens. 4 x 5 tens = 20 tens. Add the regrouped tens. 20 tens + 3 tens = 23 tens. Regroup the 24 tens as 2 hundreds and 4 tens.

4 2 x 7

H T O

1

4 2

x 7

2 9 4

Step 1: Multiply the ones.7 x 2 = 14 ones. Regroup the 14 ones as 1 tens and 4 ones.

Step 2: Multiply the tens. 7 x 4 tens = 28 tens. Add the regrouped tens. 28 tens + 1 ten = 29 tens. Regroup the 29 tens as 2 hundreds and 9 tens.

2 3 x 5

H T O

1

2 3

x 5

1 1 5

Step 1: Multiply the ones.5 x 3 = 15 ones. Regroup the 15 ones as 1 ten and 5 ones.

Step 2: Multiply the tens. 5 x 2 tens = 10 tens. Add the regrouped tens. 10 tens + 1 ten = 11 tens. Regroup the 11 tens as 1 hundred and 1 ten.

5 8 x 6

H T O

4

5 8

x 6

1 1 8

Step 1: Multiply the ones.6 x 8 = 48 ones. Regroup the 48 ones as 4 tens and 8 ones.

Step 2: Multiply the tens. 6 x 5 tens = 30 tens. Add the regrouped tens. 30 tens + 4 tens = 34 tens. Regroup the 34 tens as 3 hundreds and 4 tens.

7 2 x 8

H T O

1

7 2

x 8

5 7 6

Step 1: Multiply the ones.8 x 2 = 16 ones. Regroup the 16 ones as 1 ten and 6 ones.

Step 2: Multiply the tens. 8 x 7 tens = 56 tens. Add the regrouped tens. 56 tens + 1 ten = 57 tens. Regroup the 57 tens as 5 hundreds and 7 tens.