4.2.2 Decimals, PT3 Practice

Question 5:
Calculate the value of

\frac{4}{5} + 15.4 \div 4

and express the answer correct to one decimal place.

Solution:

\begin{array}{l} \frac{4}{5} + 15.4 \div 4 \\ = \frac{4}{5} + 3.85 \\ = 0.8 + 3.85 \\ = 4.65 \\ = 4.7 (one decimal place) \end{array}

Question 6:
Calculate the value of 84 – 3(14 + 48 ÷ 6) =

Solution:

\begin{array}{l} 84 - 3 (14 + 48 \div 6) \\ = 84 - 3 [14 + (48 \div 6)] \\ = 84 - 3 (14 + 8) \\ = 84 - 3 (22) \\ = 84 - 66 \\ = 18 \end{array}

Question 7:

Calculate the value of \frac{4 \times 0.18}{0.9} .

Solution:

\begin{array}{l} \frac{4 \times 0.18}{0.9} = \frac{0.72}{0.9} \\ = \frac{0.72 \times 10}{0.9 \times 10} \\ = \frac{7.2}{9} \\ = 0.8 \end{array}

Question 8:

\begin{array}{l} Calculate the value of (8.4 - 2.64) \div \frac{4}{3} and express the answer correct \\ to two decimal places . \end{array}

Solution:

\begin{array}{l} (8.4 - 2.64) \div \frac{4}{3} \\ = {5.76}^{1.44} \times \frac{3}{4} \\ = 4.32 \end{array}