Wednesday
Wednesday: Break it apart
Hazel finds an old quilt with 6 rows of 7 patches.
"I forget what 6 × 7 is," she says quietly.
Bennie lays a red ribbon across the quilt.
"Now there are two smaller rectangles," he says.
"6 rows of 5 on one side and 6 rows of 2 on the other."
Hazel smiles. "I know those facts! I can add the two parts."
Learn it: split a rectangle into two
Bennie splits 7 columns into 5 and 2.
The left part is 6 × 5 = 30. The right part is 6 × 2 = 12.
Add the parts: 30 + 12 = 42. So 6 × 7 = 42.
Breaking apart works because the area does not change when we split it.
- Read the question.
- Tap your answer.
6 × 7 = 6 × 5 + 6 × ?
4 × 8 = 4 × 5 + 4 × ?
7 × 9 = 7 × 5 + 7 × ?
3 × 6 = 3 × 4 + 3 × ?- Read the question.
- Tap your answer.
Learn it: shapes made of rectangles
Some shapes are made of two rectangles joined together.
Find the area of each rectangle. Then add the areas.
An L-shaped garden has a 4 by 3 part and a 2 by 5 part.
4 × 3 = 12 and 2 × 5 = 10. The area is 12 + 10 = 22 square meters.
- Read the question.
- Tap your answer.
- Think about how Bennie used the ribbon.
- Tap the steps in order.
| Sentence | True or false? |
|---|---|
| 6 × 7 = 6 × 5 + 6 × 2 | ? |
| 4 × 8 = 4 × 5 + 4 × 2 | ? |
| 7 × 5 + 7 × 4 = 63 | ? |
| Splitting a rectangle changes its area. | ? |
Fold it to make two smaller rectangles.
Find the area of each part and add them.
Clever splitting! Tomorrow Chris tells a story about walking around a garden.