Class 6 Knowing Our Numbers Exercise 1.8

\begin{array}{l} \text {Q1. Write the expression for each of the following statements using brackets: } \\ \text {(i) Four multiplied by the sum of 13 and 7 } \\ \text {(ii) Eight multiplied by the difference of four from nine. } \\ \text {(iii) Divide the difference of twenty eight and seven by 3 } \\ \text {(iv) The sum of 3 and 7 in multiplied by the difference of twelve and eight. } \\ \\\text {Sol. (i) The required expression is } 4 \times (13+7) \\ \text {(ii) The required expression is } 8 \times (9 – 4) \\ \text {(iii) The required expression is } (28 – 7) \div 3 \\ \text {(iv) The required expression is } (3 + 7) \times (12 – 8) \\ \\\text {Q2. Simplify each of the following: } \\ \text {(i) } \quad 124-(12-2) \times 9 \\ \text {(ii) } \quad (13+7) \times(9-4)-18 \\ \text {(iii) } \quad 210-(14-4) \times(18+2)-10 \\ \\\text {Sol. (i) } \quad 124- (12-2) \times 9 \\ =124 – 10 \times 9 \\ = 124 – 90 = 34 \\ \text {(ii) } \quad (13+7) \times (9-4) – 18 \\ = 20 \times 5 – 18 \\ = 100 – 18 = 82 \\ \text {(iii) } \quad 210 – (14-4) \times (18+2) -10 \\ = 210 – 10 \times 20 – 10 \\ = 210 – 200 – 10 = 0 \\ \\\end{array}