Chapter 1.5, Problem 44E

To determine

To calculate : The sum of the given expression:

  $-1117+539$

Answer to Problem 44E

  $\text{The sum of the given expression is -578}\text{.}$

Explanation of Solution

Given information :

Consider the expression provided in the question:

  $-1117+539$

Calculation :

Evaluating the expression,

One integer is positive and the other is negative.

  $\left|-1117\right|>\left|539\right|,\text{so the same sign as 1117}\text{.}$

  $-1117+539=-578$

Estimating the sum by rounding off the integers to the nearest 10;

  $\text{-1117 rounded to nearest 10 is -1120 and 539 rounded to nearest 10 is 540}\text{.}$

Therefore,

  $-1120+(-540)=-580.$

One integer is positive and the other is negative.

  $\left|-1120\right|>\left|540\right|,\text{so the same sign as 1120}\text{.}$

  $\text{-580 is a close estimation of -578}\text{.}$