5th Math: Number & Operations Base Ten practice questions and exam guide

What is 1,728 ÷ 12?

1. 124
2. 154
3. 134
4. 144

Answer: D — 144

D) Correct — Check by multiplying: 12 × 144 = 1,728. A) Check by multiplying: 12 × 124 = 1,488, which is 240 less than 1,728. B) Check by multiplying: 12 × 154 = 1,848, which is 120 more than 1,728. C) Check by multiplying: 12 × 134 = 1,608, which is 120 less than 1,728.

A gallon of paint costs $19.95. 3 gallons?

1. $59.85
2. $60.00
3. $57.85
4. $19.95

Answer: A — $59.85

A) Correct — 3 × $19.95 = $59.85. (3 × $20 = $60, minus 3 × 5¢ = 15¢.) B) Is the estimate using $20 a gallon, not the exact cost. C) Is $2.00 too low: a carrying slip in the ones place. D) Is the cost of only 1 gallon.

What is the value of the 5 in 12.345?

1. 0.005
2. 0.05
3. 5
4. 0.5

Answer: A — 0.005

A) Correct — The 5 is in the thousandths place, so it is worth 5 thousandths. B) Is the value of a 5 in the hundredths place. C) Gives the digit, not its value. D) Is the value of a 5 in the tenths place.

9.05 − 4.28 = ?

1. 4.87
2. 4.77
3. 4.67
4. 5.77

Answer: B — 4.77

B) Correct — Line up the decimal points (write 9.05 − 4.28) and subtract: 4.77. A) Is 0.1 too high: a regrouping slip in the tenths place. C) Is 0.1 too low: a regrouping slip in the tenths place. D) Is 1 too high: a regrouping slip in the ones place.

In 42.678, the 8 is in which place?

1. Tenths
2. Hundredths
3. Thousandths
4. Ones

Answer: C — Thousandths

C) Correct — The third digit after the decimal point is in the thousandths place. A) The 6 is in the tenths place. B) The 7 is in the hundredths place. D) The 2 is in the ones place.

236 × 14 = ?

1. 3,314
2. 3,204
3. 3,404
4. 3,304

Answer: D — 3,304

D) Correct — 236 × 14 = 236 × 10 + 236 × 4 = 2,360 + 944 = 3,304. A) Is 10 too high: a carrying slip in the tens place. B) Is 100 too low: a carrying slip in the hundreds place. C) Is 100 too high: a carrying slip in the hundreds place.

Which expanded form is 5.073?

1. 5 + 0.07 + 0.003
2. 5 + 0.7 + 0.03
3. 5 + 7 + 3
4. 50 + 7 + 3

Answer: A — 5 + 0.07 + 0.003

A) Correct — 5.073 has 5 ones, 0 tenths, 7 hundredths, and 3 thousandths. B) Skips the 0 in the tenths place, so each digit lands one place too far left. C) Treats every digit as ones. D) Treats the digits as tens and ones.

5 kids share $6.25 equally. How much each?

1. $31.25
2. $12.50
3. $1.05
4. $1.25

Answer: D — $1.25

D) Correct — Check by multiplying: 5 × $1.25 = $6.25. A) Multiplies by 5 instead of dividing. B) Puts the decimal point 1 place too far to the right. C) Shares the $6 as $1 each and the 25¢ as 5¢ each, but forgets the extra $1 left over.

$45.00 ÷ 4 = ?

1. $11.25
2. $10.25
3. $12.25
4. $11.00

Answer: A — $11.25

A) Correct — Check by multiplying: 4 × $11.25 = $45.00. B) Is $1.00 too low: a regrouping slip in the ones place. C) Is $1.00 too high: a regrouping slip in the ones place. D) Check by multiplying: 4 × $11.00 = $44.00, which is $1.00 less than $45.00.

0.03 × 6 = ?

1. 18
2. 1.8
3. 0.018
4. 0.18

Answer: D — 0.18

D) Correct — Multiply as whole numbers: 3 × 6 = 18. The factors have 2 decimal places in all, so the product is 0.18. A) Puts the decimal point 2 places too far to the right; count the decimal places in the factors. B) Puts the decimal point 1 place too far to the right; count the decimal places in the factors. C) Puts the decimal point 1 place too far to the left; count the decimal places in the factors.

85 × 60 = ?

1. 510
2. 5,000
3. 5,100
4. 51,000

Answer: C — 5,100

C) Correct — 85 × 60 = 85 × 6 × 10 = 510 × 10 = 5,100. A) Is 10 times too small; it leaves off a zero. B) Is 100 too low: a carrying slip in the hundreds place. D) Is 10 times too big; it has an extra zero.

When you multiply decimals, where do you count decimal places?

1. Both factors; the product gets their total
2. Only the first factor
3. Only the factor with more decimal places
4. Neither; just line up the decimal points

Answer: A — Both factors; the product gets their total

A) Correct — Count the decimal places in both factors and give the product that many. For example, 0.3 × 0.4 = 0.12. B) Leaves out the places in the second factor. C) Leaves out the places in the other factor. D) Lining up decimal points is the rule for adding and subtracting.

What is 478 × 23?

10,994.

Round 12.84 to the nearest whole number.

13.

Round 9.95 to the nearest tenth.

10.0. (Tenths 9 + round up = 10 in the ones; tenths becomes 0.)

What is 8.0 − 3.45?

4.55.

What place is the second digit after the decimal point?

Hundredths.

Compare 3.456 and 3.465. Which is greater?

3.465. Same to tenths; compare hundredths: 6 > 5.