Bruce sets up the second challenge stop near the acorn trees.
Samantha the Squirrel has packed acorns into bags for winter.
"I have 3 rows of bags, and each row holds 214 acorns," she says.
Bruce rubs his paws together. "Can anyone find the total?"
Bennie draws a long rectangle in the dirt with a stick.
"We split 214 into 200, 10 and 4," he explains.
"Each part gets its own box. Then we multiply each box."
"Last, we add the boxes together."
An area model is a rectangle split by place value.
For 3 × 214, the top shows 200, 10 and 4.
Each box is one partial product.
| × | 200 | 10 | 4 |
|---|---|---|---|
| 3 | 600 | 30 | 12 |
Add the partial products: 600 + 30 + 12 = 642.
So 3 × 214 = 642.
Four digits work the same way. There is just one more box.
For 4 × 2,316, split 2,316 into 2,000, 300, 10 and 6.
| × | 2,000 | 300 | 10 | 6 |
|---|---|---|---|---|
| 4 | 8,000 | 1,200 | 40 | 24 |
4 × 2,316 = 8,000 + 1,200 + 40 + 24 = 9,264.
Bennie checks the size. 4 × 2,000 is 8,000, so the product should be a bit more.
| Sentence | True or false? |
|---|---|
| 3 × 214 = 642 | ? |
| 2 × 1,111 = 2,222 | ? |
| 4 × 1,250 = 6,000 | ? |
| A product of 4 × 2,316 is more than 8,000. | ? |
Great work with partial products! Tomorrow we multiply two digits by two digits.