MATH REVIEW #1| Prime/Composite, Factors/Multiples, Place Value

Is the number 45 a prime or composite number?

• Prime

• Composite

• Both

• Neither

Answer explanation

The number 45 is composite because it has divisors other than 1 and itself, specifically 3, 5, 9, and 15. A prime number has only two distinct positive divisors: 1 and itself.

Is 1 a prime or composite number?

• Prime

• Composite

• Both

• Neither

Answer explanation

1 is neither prime nor composite. A prime number has exactly two distinct positive divisors (1 and itself), while a composite number has more than two. Since 1 only has one divisor, it fits neither category.

Which of the following is not a prime number?

• 3

• 9

• 11

• 47

Answer explanation

A prime number is greater than 1 and has no positive divisors other than 1 and itself. The number 9 is not prime because it can be divided by 1, 3, and 9. The other options (3, 11, 47) are all prime.

What is the purpose of a factor tree in mathematics?

• To find the sum of numbers

• To find the prime factors of a number

• To multiply numbers

• To divide numbers

Answer explanation

A factor tree is used to break down a number into its prime factors, showing the relationships between the factors. This helps in understanding the composition of the number, making 'To find the prime factors of a number' the correct choice.

The standard form of "twenty-two thousand seven hundred fifty-four" is _____

Answer explanation

The phrase 'twenty-two thousand seven hundred fifty-four' translates to the number 22,754. This is the correct standard form, matching the first answer choice.

The standard form of the number represented by 1000 + 200 + 50 + 7 is _____ .

Answer explanation

To find the standard form, simply add the numbers: 1000 + 200 + 50 + 7 = 1257. Therefore, the correct answer is 1257.

What is the expanded form of the number 65,928?

• 60,000 + 5,000 + 900 + 20 + 8

• 60,000 + 500 + 900 + 20 + 8

• 6,000 + 5,000 + 900 + 20 + 8

• 60,000 + 5,000 + 90 + 20 + 8

Answer explanation

The expanded form of 65,928 breaks down each digit by its place value: 60,000 (60 thousands), 5,000 (5 thousands), 900 (9 hundreds), 20 (2 tens), and 8 (8 ones). Thus, the correct choice is 60,000 + 5,000 + 900 + 20 + 8.

What is the place value of 3 in the number 15.3?

• 3 tenths

• 3 ones

• 3 hundredths

• 3 tens

Answer explanation

In the number 15.3, the digit 3 is in the tenths place, which represents 3 tenths (or 0.3). Therefore, the correct answer is '3 tenths'.

What is the value of 6 in 2.26 in standard form?

• 0.06

• 0.6

• 6

• 60

Answer explanation

In 2.26, the digit 6 is in the hundredths place, which represents 0.06 in standard form. Therefore, the correct answer is 0.06.

Standard form for 9 Ones + 2 Tenths + 3 Hundredths is _____

Answer explanation

To find the total, add 9 Ones (9) + 2 Tenths (0.2) + 3 Hundredths (0.03). This equals 9 + 0.2 + 0.03 = 9.23. Therefore, the correct answer is 9.23.