A rectangle can be cut into equal squares, in rows and columns.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
They must be the same size
Squares of different sizes would not be a fair way to fill it.
Count by rows
Count one row, then count the rows, exactly as with an array of counters.
Filling a rectangle with squares
Cover a rectangle with same-sized squares, leaving no gaps and no overlaps, and you have made an array out of the rectangle itself. Count the squares by rows and you have measured how much surface the rectangle covers.
Counting the tiles quickly
If a rectangle is covered by 4 rows of 6 squares, do not count all 24 one at a time. Skip-count by 6 four times: 6, 12, 18, 24. The rows and columns structure is there precisely so you do not have to count singly.
This idea is called area
The number of squares needed to cover a shape is its area. You will meet the word properly in Grade 3, but the idea is exactly what you are doing here. No gaps and no overlaps is the rule that makes the count meaningful.
Step 2: Try It Yourself
Tap and try it out.
4 + 4 + 4 = 12
3 rows of 4 makes 12.
Step 3: Watch an Example
One step at a time.
Watch Leo Fill a Rectangle
Leo fills a rectangle with same-size squares.
- Step 1
He fits 4 squares along the top row.
Step 4: Your Turn
Practice makes it stick.
The Tiled Floor
Problem 1 of 2
A floor has 5 rows of 4 tiles. How many tiles are there?
tiles
The Window
Problem 2 of 2
A window has 2 rows of 3 panes. How many panes?
panes
Count the Squares
1 of 3
4 rows of 4 squares. How many squares?
2 of 3
3 rows of 5 squares. How many squares?
3 of 3
Do the squares have to be the same size?
Step 5: Quick Check
Show what you know.
Question 1 of 2
2 rows of 5 squares. How many squares?
Question 2 of 2
How should you count the squares?
What You Learned
- A rectangle fills with same-size squares in rows and columns.
- Count one row, then count the rows.
- It is the same idea as an array of counters.