Question

lessons 2.3-2.4 review & refresh
write the words as an expression. then evaluate the expression.

1. subtract 5 from the product of 6 and 8.
2. subtract the quotient of 21 and 7 from 10.
3. multiply by 5 the sum of 12 and 15.
4. multiply the sum of 6 and 4 by the difference of 8 and 3.

write your answer as a fraction and as a decimal.

1. from a stack of 100 paper plates, 42 were used at a picnic. what portion of the paper plates were used?
2. a computer lab had 1,000 sheets of paper for the printer. last month, 378 sheets of paper were used. what portion of the sheets of paper were not used?

insert parentheses to make the statement true.

1. $6 + 3 \times 4 - 2 = 34$
2. $6 + 3 \times 4 - 2 = 12$
3. round 17.394.

nearest whole number:
nearest tenth:
nearest hundredth:

1. round 6.708.

nearest whole number:
nearest tenth:
nearest hundredth:

Explanation:

Step1: Convert to expression, evaluate

$6 \times 8 - 5 = 48 - 5 = 43$

Step2: Convert to expression, evaluate

$10 - (21 \div 7) = 10 - 3 = 7$

Step3: Convert to expression, evaluate

$5 \times (12 + 15) = 5 \times 27 = 135$

Step4: Convert to expression, evaluate

$(6 + 4) \times (8 - 3) = 10 \times 5 = 50$

Step5: Find fraction, convert to decimal

$\frac{42}{100} = \frac{21}{50} = 0.42$

Step6: Find unused, convert to decimal

$1000 - 378 = 622$, $\frac{622}{1000} = \frac{311}{500} = 0.622$

Step7: Insert parentheses for truth

$(6 + 3) \times 4 - 2 = 34$

Step8: Insert parentheses for truth

$6 + 3 \times (4 - 2) = 12$

Step9: Round 17.394

Nearest whole: $17$, Nearest tenth: $17.4$, Nearest hundredth: $17.39$

Step10: Round 6.708

Nearest whole: $7$, Nearest tenth: $6.7$, Nearest hundredth: $6.71$

Answer:

1. $6 \times 8 - 5 = 43$
2. $10 - (21 \div 7) = 7$
3. $5 \times (12 + 15) = 135$
4. $(6 + 4) \times (8 - 3) = 50$
5. Fraction: $\frac{21}{50}$, Decimal: $0.42$
6. Fraction: $\frac{311}{500}$, Decimal: $0.622$
7. $(6 + 3) \times 4 - 2 = 34$
8. $6 + 3 \times (4 - 2) = 12$
9. Nearest whole number: $17$; Nearest tenth: $17.4$; Nearest hundredth: $17.39$
10. Nearest whole number: $7$; Nearest tenth: $6.7$; Nearest hundredth: $6.71$