Rational Numbers
Which number is NOT rational?
A. 5
B. 1/2
C. 0.75
D. √2
Answer: D — √2
0.5 × 4 = ?
A. 0.20
B. 2
C. 20
D. 0.2
Answer: B — 2
1/2 × 1/3 = ?
A. 1/5
B. 2/6
C. 1/6
D. 2/3
Answer: C — 1/6
6 ÷ 2 = ?
A. 2
B. 3
C. 4
D. 12
Answer: B — 3
Which is greater?
0.6 or 3/5
A. 0.6
B. 3/5
C. They are equal
D. Cannot be determined
Answer: C
⭐ Explain:
3/5 = 0.6
Classify the number:
−7
A. Natural number only
B. Whole number
C. Integer and rational number
D. Irrational number
Answer: C
2.4 × 3 = ?
A. 0.72
B. 7.2
C. 72
D. 6.4
Answer: B — 7.2
2/3 × 3/4 = ?
A. 6/12
B. 1/2
C. 5/7
D. 2/7
Answer: B — 1/2
4.8 ÷ 2 = ?
A. 1.4
B. 2.4
C. 2.8
D. 24
Answer: B — 2.4
What is:
0.25 × 4/5
A. 0.05
B. 0.20
C. 1.00
D. 2.00
Answer: B — 0.20
⭐ Explain:
0.25 × 0.8 = 0.20
Which list contains only rational numbers?
A. √2, π, √5
B. 1/2, −3, 0.25
C. π, 4, √9
D. √7, 2.5, π
Answer: B
1.25 × 0.4 = ?
A. 0.05
B. 0.5
C. 5
D. 50
Answer: B — 0.5
3/5 × 10/9 = ?
A. 30/45
B. 2/3
C. 13/14
D. 3/2
Answer: B — 2/3
7.5 ÷ 0.5 = ?
A. 1.5
B. 3.75
C. 15
D. 150
Answer: C — 15
Which answer is closest to:
3/4 × 2.4
A. 1.2
B. 1.8
C. 2.4
D. 3.2
Answer: B — 1.8
Classify 0 using the most specific classifications that apply.
A. Whole and rational
B. Integer and rational
C. Whole, integer, and rational
D. Natural, whole, integer, and rational
Answer: C
3.6 × 2.15 = ?
A. 7.74
B. 7.14
C. 77.4
D. 6.74
Answer: A — 7.74
2 1/2 × 3/4 = ?
A. 1 7/8
B. 2 3/4
C. 3 1/4
D. 1 1/4
Answer: A — 1 7/8
⭐ Reminder:
Convert the mixed number first:
2 1/2 = 5/2
Then:
5/2 × 3/4 = 15/8 = 1 7/8
12.6 ÷ 0.3 = ?
A. 4.2
B. 42
C. 420
D. 0.42
Answer: B — 42
⭐ Reminder:
Move the decimal in both numbers one place:
12.6 ÷ 0.3 → 126 ÷ 3 = 42
A student has 4.5 pounds of candy. She divides it equally into bags containing 0.75 pounds each.
How many bags can she make?
A. 4
B. 5
C. 6
D. 7
Answer: C — 6
⭐ Explain:
4.5 ÷ 0.75 = 6
Which statement is TRUE?
A. Every irrational number is an integer.
B. Every integer is a rational number.
C. Every rational number is a whole number.
D. Every decimal is irrational.
Answer: B
⭐ Explain:
An integer can always be written as a fraction with a denominator of 1.
Example:
−5 = −5/1
A notebook costs $2.75. A teacher buys 8 notebooks.
How much does the teacher spend?
A. $20.00
B. $21.50
C. $22.00
D. $22.50
Answer: C — $22.00
⭐ Explain:
2.75 × 8 = 22.00
A recipe requires 3/4 cup of flour for one batch. You want to make 2 1/2 batches.
How much flour do you need?
A. 1 1/4 cups
B. 1 7/8 cups
C. 2 1/4 cups
D. 3 1/4 cups
Answer: B — 1 7/8 cups
⭐ Explain:
3/4 × 2 1/2
3/4 × 5/2 = 15/8 = 1 7/8
A 15.6-meter rope is cut into pieces that are 1.2 meters long.
How many pieces can be made?
A. 12
B. 13
C. 14
D. 18
Answer: B — 13 pieces
⭐ Explain:
15.6 ÷ 1.2
Move both decimals one place:
156 ÷ 12 = 13
FINAL CHALLENGE
A school orders 3 1/2 boxes of pencils.
Each box contains 2.4 pounds of supplies.
The supplies are divided equally among 7 classrooms.
How many pounds of supplies does each classroom receive?
Step 1:
Convert the mixed number:
3 1/2 = 3.5
Step 2:
Multiply:
3.5 × 2.4 = 8.4
Step 3:
Divide:
8.4 ÷ 7 = 1.2
Answer:
B. 1.2 pounds