Arithmetic and Number Sense Flashcards

What is the greatest common factor (GCF) of 48 and 36?

Answer: 12

The prime factorizations are 48 = 2⁴ × 3 and 36 = 2² × 3², giving GCF = 2² × 3 = 12.

A shirt costs $45 and is on sale for 20% off. What is the sale price?

Answer: $36

20% of $45 = $9 discount; $45 - $9 = $36.

Which of the following is NOT a prime number?

Answer: 33

33 = 3 × 11, so it has factors other than 1 and itself and is not prime.

Compute: 3.6 ÷ 0.04

Answer: 90

3.6 ÷ 0.04 = 360 ÷ 4 = 90 (multiply both by 100).

What is the ratio of 2 hours to 45 minutes in simplest form?

Answer: 8:3

2 hours = 120 minutes; 120:45 simplifies by dividing by 15 to give 8:3.

Evaluate: 4! (4 factorial)

Answer: 24

4! = 4 × 3 × 2 × 1 = 24.