Multiply 2-digit Numbers Lesson 10.3
Solve use a strategy called Regrouping STEP 1 Multiply the ones. Put the tens ( 3 ) above the tens place. 3 1 6 x 5 0 STEP 2 Multiply the tens, then add the regrouped  3  to the product. 3 1 6 x  5 8 0
Multiplication Steps 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.  H T O 3 5 9 x 4 2 3 6
42 x 7 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.  H T O 1 4 2 x 7 2 9 4
23 x 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.  H T O 1 2 3 x 5 1 1 5
58 x 6 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.  H T O 4 5 8 x 6 1 1 8
72 x 8 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.  H T O 1 7 2 x 8 5 7 6

Math10.3

  • 1.
  • 2.
    Solve use astrategy called Regrouping STEP 1 Multiply the ones. Put the tens ( 3 ) above the tens place. 3 1 6 x 5 0 STEP 2 Multiply the tens, then add the regrouped 3 to the product. 3 1 6 x 5 8 0
  • 3.
    Multiplication Steps Step1: 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. H T O 3 5 9 x 4 2 3 6
  • 4.
    42 x 7Step 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. H T O 1 4 2 x 7 2 9 4
  • 5.
    23 x 5Step 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. H T O 1 2 3 x 5 1 1 5
  • 6.
    58 x 6Step 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. H T O 4 5 8 x 6 1 1 8
  • 7.
    72 x 8Step 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. H T O 1 7 2 x 8 5 7 6