Number and the Number System

What is the value of the digit 7 in the number 47,325?

• A7
• B70
• C700
• D7,000✓

Answer: The 7 is in the thousands place, so its value is 7 × 1,000 = 7,000.

Round 38.67 to the nearest whole number.

• A38
• B39✓
• C38.5
• D40

Answer: The decimal part is 0.67, which is greater than 0.5, so round up to 39.

Which of the following is the smallest? -5, -2, 0, 3

• A-5✓
• B-2
• C0
• D3

Answer: -5 is the smallest because it is furthest to the left on a number line.

What is 156 + 347?

• A403
• B503✓
• C489
• D512

Answer: 156 + 347 = 503. Line up the digits and add: 6+7=13 (write 3, carry 1), 5+4+1=10 (write 0, carry 1), 1+3+1=5.

What is 725 - 287?

• A438✓
• B448
• C412
• D512

Answer: 725 - 287 = 438. Subtract: 5-7 (borrow, so 15-7=8), 1-8 (borrow, so 11-8=3), 6-2=4.

What is 23 × 4?

• A92✓
• B82
• C102
• D84

Answer: 23 × 4 = (20 × 4) + (3 × 4) = 80 + 12 = 92.

What is 84 ÷ 7?

• A10
• B11
• C12✓
• D13

Answer: 84 ÷ 7 = 12, because 7 × 12 = 84.

Round 2,456 to the nearest 100.

• A2,400
• B2,460
• C2,500✓
• D2,450

Answer: Look at the tens digit (5). Since it is 5 or more, round up. 2,456 rounds to 2,500.

What is the place value of 3 in 5.03?

• AUnits
• BTenths
• CHundredths✓
• DThousandths

Answer: The 3 is two places after the decimal point, so it is in the hundredths place.

Order these numbers from smallest to largest: 2.5, 2.05, 2.50, 2.5

• A2.05, 2.5, 2.50, 2.5✓
• B2.05, 2.50, 2.5, 2.5
• C2.05, 2.5, 2.5, 2.50
• DAll the same order

Answer: 2.05 is smallest. 2.5, 2.50, and 2.5 are all equal (2.50 = 2.5).

What is -3 + 8?

• A-11
• B5✓
• C11
• D-5

Answer: Starting at -3 on a number line, move 8 places to the right: -3 + 8 = 5.

What is 5 - (-2)?

• A3
• B-7
• C7✓
• D-3

Answer: Subtracting a negative is the same as adding: 5 - (-2) = 5 + 2 = 7.