Partial Product Multiplication Algorithm Review of Partial Products

  • Slides: 17
Download presentation
Partial Product (Multiplication Algorithm)

Partial Product (Multiplication Algorithm)

Review of Partial Products 1. 2. 3. 4. Set up the problem vertically. Separate

Review of Partial Products 1. 2. 3. 4. Set up the problem vertically. Separate all parts. Find the products. Add to find the sum.

Here’s an example. 82 (80+2) (3) x 3_ 240 = 80 x 3 +_____

Here’s an example. 82 (80+2) (3) x 3_ 240 = 80 x 3 +_____ 6 =2 x 3 246

Try this one using your slate. Use the blank worksheet to help guide you.

Try this one using your slate. Use the blank worksheet to help guide you. 42 (40+2) (3) x 120 = 40 x 3 3_ 6 =2 x 3 +_____ 126

Try another one using your slate. Use the blank worksheet to help guide you.

Try another one using your slate. Use the blank worksheet to help guide you. 71 x 4_ (70+1) (4) 280 = 70 x 4 4 =1 x 4 +_____ 284

Now, we are going to learn to multiply a 2 digit number by a

Now, we are going to learn to multiply a 2 digit number by a 2 digit number using the Partial Products Algorithm.

We will use the same steps: 1. 2. 3. 4. Set up the problem

We will use the same steps: 1. 2. 3. 4. Set up the problem vertically. Separate all parts. Find the products. Add to find the sum.

Here’s an example. 25 (20 + 5) x 32 (30 + 2) 600 =

Here’s an example. 25 (20 + 5) x 32 (30 + 2) 600 = 20 x 30 Find the products. Add. 10 = 5 x 2 40 = 20 x 2 +_____ 150 = 5 x 30 800 You must separate and multiply all parts. Remember this phrase: Down, down, crisscross

Here’s another example. 54 (50 + 4) x 23 (20 + 3) 1000 =

Here’s another example. 54 (50 + 4) x 23 (20 + 3) 1000 = 50 x 20 Find the products. Add. 12 = 4 x 3 150 = 50 x 3 +_____ 80 = 4 x 20 1242 You must multiply all parts. Remember this phrase: Down, down, crisscross

Here is another way of looking at the problem.

Here is another way of looking at the problem.

When multiplying by “Partial Products, ” you must first multiply parts of these numbers,

When multiplying by “Partial Products, ” you must first multiply parts of these numbers, then you add all of the results to find the answer. Multiply 20 X 60 (tens by tens) Multiply 60 X 7 (tens by ones) Multiply 4 X 20 (ones by tens) Multiply 7 X 4 (ones by ones) Add the results 2 7 (20+7) X 6 4 (60+4) 1, 200 420 80 + 28 1, 728

When multiplying by “Partial Products, ” you must first multiply parts of these numbers,

When multiplying by “Partial Products, ” you must first multiply parts of these numbers, then you add all of the results to find the answer. Multiply 40 X 50 (tens by tens) Multiply 50 X 8 (tens by ones) Multiply 3 X 40 (ones by tens) Multiply 8 X 3 (ones by ones) Add the results 4 8 (40+8) X 5 3 (50+3) 2, 000 400 120 + 24 2, 544

When multiplying by “Partial Products, ” you must first multiply parts of these numbers,

When multiplying by “Partial Products, ” you must first multiply parts of these numbers, then you add all of the results to find the answer. Multiply 60 X 50 (tens by tens) Multiply 50 X 9 (tens by ones) Multiply 8 X 60 (ones by tens) Multiply 9 X 8 (ones by ones) Add the results 6 9 (60+9) X 5 8 (50+8) 3, 000 450 480 + 72 4, 002

Now it’s time to try some on your own! Use the blank paper to

Now it’s time to try some on your own! Use the blank paper to guide you. Separate the parts. Multiply (down, crisscross) Add. 59 (50 + 9) x 14 (10 + 4) 500 = 50 x 10 36 = 9 x 4 200 = 50 x 4 90 = 9 x 10 +_____ 826

Another! Use the blank paper to guide you. Separate the parts. Multiply (down, crisscross)

Another! Use the blank paper to guide you. Separate the parts. Multiply (down, crisscross) Add. 84 (80 + 4) x 26 (20 + 6) 1600 = 80 x 20 24 = 4 x 6 480 = 80 x 6 80 = 4 x 20 +_____ 2184

Last One! Use the blank paper to guide you. Separate the parts. Multiply (down,

Last One! Use the blank paper to guide you. Separate the parts. Multiply (down, crisscross) Add. 75 (70 + 5) x 48 (40 + 8) 2800 = 70 x 40 40 = 5 x 8 560 = 70 x 8 200 = 5 x 40 +_____ 3600

Homework * You will complete a worksheet with 4 multiplication problems which you will

Homework * You will complete a worksheet with 4 multiplication problems which you will use Partial Products to solve.