Decimals

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}

Question 1:
62.4 – 36.02 + 12.6 =

Solution:

Question 2:
4.76 × 7.2 ÷ 0.3 =

Solution:

\begin{array}{l} 4.76 \times 7.2 \div 0.3 \\ = 34.272 \div 0.3 \\ = \frac{34.272}{0.3} \\ = \frac{34.272 \times 10}{0.3 \times 10} \\ = \frac{342.72}{3} \\ = 114.24 \end{array}

Question 3:
0.12 × (5.9 – 1.33) ÷ 0.8 =

Solution:

\begin{array}{l} 0.12 \times (5.9 - 1.33) \div 0.8 \\ = 0.12 \times 4.57 \div 0.8 \\ = 0.5484 \div 0.8 \\ = \frac{0.5484}{0.8} \\ = \frac{0.5484 \times 10}{0.8 \times 10} \\ = \frac{5.484}{8} \\ = 0.6855 \end{array}

Question 4:
14.83 + (20.04 – 10.68) ÷ 1.8 =

Solution:

\begin{array}{l} 14.83 + (20.04 - 10.68) \div 1.8 \\ = 14.83 + 9.36 \div 1.8 \\ = 14.83 + \frac{9.36 \times 10}{1.8 \times 10} \\ = 14.83 + \frac{93.6}{18} \\ = 14.83 + 5.2 \\ = 20.03 \end{array}

4.2.2 Decimals, PT3 Practice