Multiplying Up To 4 Digits (Area Model)

7 × 8 means 7 groups of 8, or 8 + 8 + 8 + 8 + 8 + 8 + 8.

(5 + 2) × 8 = 40 + 16 = 56

I could draw a rectangle with 7 rows and 8 columns. There are 56 squares. The product is 56.

A rectangle with width 7 units and length 8 units has an area of 56 square units.

There are 6 groups of 5 tens, which is 30 tens. 30 tens is 300. 6 × 50 = 300.

I could draw a rectangle and divide it into two sections. At the top I write 30 and 5. At the left side I write 9. Then I multiply 9 × 30, which is 270, and multiply 9 × 5, which is 45. Then I add the partial products: 270 + 45 = 315. 9 × 35 = 315.

The number 35 is 3 tens and 5 ones. The left box is tens, so I write 30, and the right box is ones, so I write 5.

I would need 2 more boxes, one for the hundreds place and one for the thousands place. Then I would label them 4,000 and 700. Then I can multiply 9 × 4,000, which is 36,000, and 9 × 700, which is 6,300. Then I add all four partial products: 36,000 + 6,300 + 270 + 45 = 42,615. 9 × 4,735 = 42,615.

I could draw a rectangle and divide it into four sections. At the top I would write 80 and 1 above the two sections. At the top left side I would write 20 and the bottom left side I would write 6. Then I multiply in each section: 20 × 80 = 1,600, 20 × 1= 20, 6 × 80 = 480, and 6 × 1 = 6. Then add the parts: 1,600 + 20 + 480 + 6 = 2,106. So 26 × 81 = 2,106.

No. She multiplied 50 × 30 = 1,500 and 7 × 4 = 28. She left out two more partial products: 50 × 4 = 200 and 7 × 30 = 210. The product is 1,938.