Tuesday
Tuesday: Multiply to find area
Hazel wants a bigger quilt, 6 rows of 8 patches.
"Counting every patch will take so long," she sighs.
Bennie taps the edge of the quilt.
"Each row has 8 patches, and there are 6 rows," he says.
"That is 6 groups of 8. We can multiply!"
Hazel takes the pencil from behind her ear. "6 × 8 = 48," she writes.
Learn it: rows times squares in a row
A rectangle of unit squares is an array.
Rows times squares in each row gives the area.
This is the same as length times width.
Hazel's quilt has 6 rows of 8 squares.
6 × 8 = 48, so the area is 48 square units.
Counting one by one also gives 48. Multiplying is just quicker to write.
This rectangle is 7 cm long and 5 cm wide. 7 × 5 = 35 square centimeters.
- Read the question.
- Tap your answer.
What is the area in square centimeters?
What is the area in square inches?
What is the area in square meters?
What is the area in square feet?
What is the area in square centimeters?- Read the question.
- Tap your answer.
Find the missing side
If you know the area and one side, think of a times fact.
Say the area is 24 and one side is 6.
6 × 4 = 24, so the other side is 4.
- Read the question.
- Tap your answer.
| Sentence | True or false? |
|---|---|
| 6 × 8 = 48 | ? |
| The area of a 7 by 5 rectangle is 12 square units. | ? |
| Multiplying gives the same area as counting every square. | ? |
| 9 × 4 = 36 | ? |
Count the rows. Count how many are in one row.
Multiply to find how many in all.
Count them one by one to check.
Great multiplying! Tomorrow we break big rectangles into smaller ones.