Chapter 1.1, Problem 3EE

E. Calculator Problems

You probably own a calculator and, of course, you are eager to put it to work doing practical math calculations. In this text we include problem sets for calculator users. These problems are taken from real-life situations and, unlike most textbook problems, involve big numbers and lots of calculations. If you think that having an electronic brain-in-a-box means that you do not need to know basic arithmetic, you will be disappointed. The calculator helps you to work faster, but it will not tell you what to do or how to do it.

Detailed instructions on using a calculator with whole numbers appears on page 68.

Here are a few helpful hints for calculator users:

1. 1. Always estimate your answer before doing a calculation.
2. 2. Check your answer by comparing it with the estimate or by the other methods shown in this text. Be certain that your answer makes sense.
3. 3. If you doubt the calculator (they do break down, you know), put a problem in it whose answer you know, preferably a problem like the one you are solving.

Add the following as shown.

1. (a) $\begin{array}{l}\text{\$137427}\\ \text{67429}\\ \text{91006}\\ \text{6070}\\ \text{4894}\\ \underset{\_}{\text{399}}\end{array}$
2. (b) $\begin{array}{l}\text{\$216847}\\ \text{386738}\\ \text{86492}\\ \text{28104}\\ \text{9757}\\ \underset{\_}{\text{4875}}\end{array}$
3. (c) $\begin{array}{l}\text{\$693884}\\ \text{675489}\\ \text{560487}\\ \text{276921}\\ \text{44682}\\ \underset{\_}{\text{47039}}\end{array}$
4. (d) $4299 + $137 + $20 + $177 + $63 + $781 + $1008 + $671 = ?