Question

Add:
(i) $\begin{array}{c}\begin{array}{cccc}-& 2& 0& 6\end{array}\\ \begin{array}{cccc}+& & 9& 8\end{array}\\ \underline{\overline{\begin{array}{cccc}& & & \end{array}}}\end{array}$

(ii)$\begin{array}{c}\begin{array}{cccc}+& 1& 7& 8\end{array}\\ \begin{array}{cccc}-& & 6& 9\end{array}\\ \underline{\overline{\begin{array}{cccc}& & & \end{array}}}\end{array}$

(iii)$\begin{array}{c}\begin{array}{cccc}-& 1& 0& 3\end{array}\\ \begin{array}{cccc}+& 3& 1& 2\end{array}\\ \underline{\overline{\begin{array}{cccc}& & & \end{array}}}\end{array}$

(iv) $\begin{array}{c}\begin{array}{cccc}-& 4& 9& 3\end{array}\\ \begin{array}{cccc}+& 2& 8& 9\end{array}\\ \underline{\overline{\begin{array}{cccc}& & & \end{array}}}\end{array}$

Answer 1

i)
$$\begin{gathered} \begin{array}{l}-206\\ \frac{+\mathrm{98}}{-108}\\ \mathrm{Since}\mathrm{we}\mathrm{are}\mathrm{adding}\mathrm{a}\mathrm{negative}\mathrm{number}\mathrm{with}\mathrm{a}\mathrm{positive}\mathrm{number},\\ \mathrm{we}\mathrm{shall}\mathrm{subtract}\mathrm{the}\mathrm{smaller}\mathrm{number},\mathrm{i}.\mathrm{e}.98\mathrm{from}\mathrm{the}\mathrm{greater}\mathrm{number},\mathrm{i}.\mathrm{e}.206\\ 206-98=108\\ \mathrm{Since}\mathrm{the}\mathrm{greater}\mathrm{number}\mathrm{is}\mathrm{negative},\mathrm{the}\mathrm{sign}\mathrm{of}\mathrm{the}\mathrm{result}\mathrm{will}\mathrm{be}\mathrm{negative}. \\ \mathrm{So},\mathrm{the}\mathrm{answer}\mathrm{will}\mathrm{be}-108\end{array} \end{gathered}$$

ii)
$\begin{array}{l}178\\ \frac{\text{-69}}{\text{1}0\text{9}}\end{array}$
$$\begin{gathered} \begin{array}{l}\text{Since we are adding a negative number with a positive number,}\\ \text{we shall subtract the smaller number, i.e. 69, from the greater number, i.e. 178}\\ \text{178 - 69 = 109}\\ \mathrm{Since\; the\; greater\; number\; is\; positive,\; the\; sign}\text{of the result will be positive.}\end{array} \\ \mathrm{So,}\mathrm{the}\mathrm{answer\; will\; be\; 109} \end{gathered}$$

(iii)

$\begin{array}{l}312\\ \text{-}\frac{103}{\underset{}{209}}\\ \end{array}$
Since we are adding a negative number with a positive number,
we shall subtract the smaller number, i.e. -103, from the greater number, i.e. 312
312 - 103 = 209
Since the greater number is positive, the sign of the result will be positive.
So, the answer will be 209

$\begin{array}{l}\left(iv\right)\\ -493\\ \frac{+289}{-204}\end{array}$

Since we are adding a negative number with a positive number,
we shall subtract the smaller number, i.e. 289, from the greater number, i.e. 493.
493 - 289 = 204
Since the greater number is negative, the sign of the result will be negative.
So, the answer will be -204