1. Finding the Area of Rectangles
5.NF.B.4

2. 3 3 12 sq. units Finding the Area of Rectangles 1 2 1 2 1 4 10 9 ½ 9
This rectangle is 3 ½ units wide and 3 ½ units long. What is its area?
This is one square unit.
This is one half of a square unit.
This is also one half of a square unit.
This is one fourth of a square unit.
Let’s count square units to find the area. 1 2 3 4 5 6 7 8 9
9 ½ 10
10 ½ 11
11 ½ 12
12 ¼
The area of this shape is 12 ¼ square units. 1 4 12
sq. units 10
9 ½ 9
10 ½
12 ¼
The area of this shape is 12 ¼ square units. 8 12
11 ½ 11 5
This is also one half of a square unit.
This is one fourth of a square unit.
This is one half of a square unit.
This is one square unit.
This rectangle is 3 ½ units wide and 3 ½ units long. What is its area?
Let’s count square units to find the area. 1 6 4 3 2 7

3. Finding the Area of Rectangles6 6 1 2 1 2 3 3 × 1 2 3 7 2 7 2 49 × = 1 2 3 4
We can also multiply 3 ½ by 3 ½ to find the area.
First, let’s convert the mixed numbers in this equation to improper fractions.
2 x 3 = ?
6. The whole number 3 is equal to 6 halves.
Add 1 more half …
… to get to 7/2.
… to get 7/2.
7 x 7 is …? 49
2 x 2 is … 4
49 divided by 4 is equal to …
12 remainder 1
And the remainder 1 …
… out of 4 …
… means ¼.
So, again, we see that the area is 12 ¼ square units. 12
R 1 1 4 1 4 12
sq. units 4 49
12 remainder 1
49 divided by 4 is equal to …
And the remainder 1 … 4
… means ¼.
So, again, we see that the area is 12 ¼ square units.
2 x 2 is …
… out of 4 …
We can also multiply 3 ½ by 3 ½ to find the area.
Add 1 more half …
6. The whole number 3 is equal to 6 halves.
2 x 3 = ?
First, let’s convert the mixed numbers in this equation to improper fractions.
… to get to 7/2.
2 x 3 = ?
7 x 7 is …?
… to get 7/2.
Add 1 more half …
6. The whole number 3 is equal to 6 halves. 49

4. 5 13 sq. units Finding the Area of Rectangles 1 2 1 2 3 4 13
This rectangle is 5 ½ units wide and 2 ½ units long. What is its area?
Let’s count square units to find the area. 10
10 ½ 11
11 ½ 12
12 ½ 13
13 ½
13 ¾
The area of this shape is 13 ¾ square units. 3 4 13
sq. units 13
The area of this shape is 13 ¾ square units.
12 ½
13 ¾
13 ½ 11
Let’s count square units to find the area.
This rectangle is 5 ½ units wide and 2 ½ units long. What is its area? 10
10 ½
11 ½ 12

5. Finding the Area of Rectangles10 4 1 2 1 2 5 2 × 1 2 5 11 2 5 2 55 × = 1 2 4
We can also multiply 5 ½ by 2 ½ to find the area.
First, let’s convert mixed numbers in this equation to improper fractions.
2 x 5 = ? 10
Add 1 more half …
… to get 11/2.
2 x 2 = ? 4
… to get 5/2.
11 x 5 is … 55
2 x 2 is …
55 divided by 4 is equal to …
13 remainder 3
And the remainder 3 …
… out of 4 …
… means ¾.
So, again, we see that the area is 13 ¾ square units. 13
R 3 3 4 3 4 13
sq. units 4 55
… out of 4 …
And the remainder 3 …
… means ¾.
So, again, we see that the area is 13 ¾ square units.
13 remainder 3
… to get 5/2.
Add 1 more half … 10
Add 1 more half …
… to get 11/2.
2 x 5 = ?
First, let’s convert mixed numbers in this equation to improper fractions.
We can also multiply 5 ½ by 2 ½ to find the area.
2 x 2 = ? 4 4
2 x 2 is … 55
11 x 5 is …
55 divided by 4 is equal to …

6. 3 5 16 sq. units Finding the Area of Rectangles 1 2 1 2 12
This rectangle is 3 units wide and 5 ½ units long. What is its area?
Let’s count square units to find the area. 15
15 ½ 16
16 ½
The area of this shape is 16 ½ square units. 1 2 16
sq. units 12
The area of this shape is 16 ½ square units. 9 3
Let’s count square units to find the area.
This rectangle is 3 units wide and 5 ½ units long. What is its area? 15
15 ½
16 ½ 16 6

7. Finding the Area of Rectangles10 1 2 3 5 3 × 5 1 2 3 1 11 2 33 × = 2
We can also multiply 3 by 5½ to find the area.
First, let’s convert the mixed number in this equation to an improper fraction.
3 is equal to …
3/1
2 x 5 = ? 10
Add 1 more half …
… to get 11/2.
3 x 11 is … 33
1 x 2 is … 2
33 divided by 2 is equal to …
16 remainder 1
And the remainder 1 …
… out of 2 …
… means 1/2.
So, again, we see that the area is 16 ½ square units. 16
R 1 1 2 1 2 16
sq. units 2 33
So, again, we see that the area is 16 ½ square units.
… means 1/2.
… to get 11/2.
… out of 2 …
Add 1 more half …
2 x 5 = ?
3 is equal to … 10
3/1
First, let’s convert the mixed number in this equation to an improper fraction.
We can also multiply 3 by 5½ to find the area.
3 x 11 is … 33
16 remainder 1
33 divided by 2 is equal to … 2
1 x 2 is …
And the remainder 1 …

8. Finding the Area of Rectangles4 16 1 2 × 4 1 4 1 2 5 2 17 4 85 × = 8
To find the area of this rectangle, we can multiply the length by the width.
2 ½ x 4 ¼
2 x 2 = ?
4. The whole number 2 is equal to 4 halves.
Add 1 more half …
… to get 5/2.
4 x 4 = …
16. The whole number 4 is equal to 16/4.
Add 1 more fourth …
… to get 17/4.
5 x 17 is … 85
2 x 4 is … 8
85 divided by 8 is equal to …
10 remainder 5
And the remainder 5 …
… out of 8 …
… means 5/8.
So, the area is 10 and 5/8 square units. 5 8 10
sq. units 10
R 5 5 8 8 85
10 remainder 5
85 divided by 8 is equal to … 8
And the remainder 5 …
… out of 8 …
So, the area is 10 and 5/8 square units.
… means 5/8.
2 x 4 is …
2 x 2 = ?
4. The whole number 2 is equal to 4 halves.
Add 1 more fourth …
2 ½ x 4 ¼
To find the area of this rectangle, we can multiply the length by the width.
Add 1 more half …
… to get 5/2.
5 x 17 is …
… to get 17/4.
16. The whole number 4 is equal to 16/4.
4 x 4 = … 85

9. Finding the Area of Rectangles15 9 1 3 5 × 1 3 5 1 3 16 3 10 3
160 × = 9
To find the area of this rectangle, we can multiply the length by the width.
5 1/3 x 3 1/3
3 x 5 = ?
15. The whole number 5 is equal to 15/3.
Add 1 more third …
… to get 16/3.
3 x 3 = ?
9. The whole number 3 is equal to 9/3.
… to get 10/3.
16 x 10 is …
160
3 x 3 is … 9
160 divided by 9 is equal to …
17 remainder 7
And the remainder 7 …
… out of 9 …
… means 7/9.
So, the area is 17 and 7/9 square units. 7 9 17
sq. units 17
R 7 7 9 9
160 9
17 remainder 7
And the remainder 7 …
3 x 3 is …
So, the area is 17 and 7/9 square units.
160
… means 7/9.
… out of 9 …
To find the area of this rectangle, we can multiply the length by the width.
5 1/3 x 3 1/3
Add 1 more third …
9. The whole number 3 is equal to 9/3.
160 divided by 9 is equal to …
3 x 5 = ?
15. The whole number 5 is equal to 15/3.
… to get 10/3.
3 x 3 = ?
… to get 16/3.
Add 1 more third …
16 x 10 is …

10. Finding the Area of Rectangles8 10 1 2 4 × 5 1 5 2 1 2 4 9 2 11 5 99 × = 10
To find the area of this rectangle, we can multiply the length by the width.
4 1/2 x 2 1/5
2 x 4 = ?
8. The whole number 4 is equal to 8/2.
Add 1 more half …
… to get 9/2
5 x 2 = ?
10. The whole number 2 is equal to 10/5.
Add 1 more fifth …
… to get 11/5.
9 x 11 is … 99
2 x 5 is … 10
99 divided by 10 is equal to …
9 remainder 9
And the remainder 9 …
… out of 10 …
… means 9/10.
So, the area is 9 and 9/10 square units. 9 10 9
R 9 9 10
sq. units 10 99
2 x 5 is …
9 remainder 9 10
… out of 10 … 99
So, the area is 9 and 9/10 square units.
… means 9/10.
And the remainder 9 …
… to get 9/2
To find the area of this rectangle, we can multiply the length by the width.
99 divided by 10 is equal to …
10. The whole number 2 is equal to 10/5.
Add 1 more fifth …
4 1/2 x 2 1/5
2 x 4 = ?
… to get 11/5.
5 x 2 = ?
Add 1 more half …
8. The whole number 4 is equal to 8/2.
9 x 11 is …

11. Finding the Area of Rectangles
Closing Question

12. Finding the Area of Rectangles2 24 1 2 1 2 × 4 6 1 4 6 3 2 25 4 75 × = 8
To find the area of this rectangle, we can multiply the length by the width.
1 ½ x 6 ¼
2 x 1 = ? 2
Add 1 more half …
… to get 3/2.
4 x 6 = ? 24
Add 1 more fourth …
… to get 25/4.
3 x 25 is … 75
2 x 4 is … 8
75 divided by 8 is equal to …
9 remainder 3
And the remainder 3 …
… out of 8 …
… means 3/8.
So, the area is 9 and 3/8 square units. 3 8 9 9
R 3 3 8
sq. units 8 75
9 remainder 3 8
And the remainder 3 …
So, the area is 9 and 3/8 square units.
2 x 4 is …
… means 3/8.
… out of 8 …
1 ½ x 6 ¼
To find the area of this rectangle, we can multiply the length by the width.
2 x 1 = ?
Add 1 more fourth … 24
75 divided by 8 is equal to … 2
Add 1 more half …
3 x 25 is …
… to get 25/4.
4 x 6 = ?
… to get 3/2. 75