Page 69 - MarceAlgebra Demystified

56 CHAPTER 3 Decimals

3. 0:6 ¼

4. 0:289421 ¼

Solutions

171
1: 1:71 ¼ 1 71 ¼
100 100
34,598
2: 34:598 ¼ 34 598 ¼
1000 1000
6
3: 0:6 ¼
10
289,421
4: 0:289421 ¼
1,000,000
There are two types of decimal numbers, terminating and nonterminating.
The above examples and practice problems are terminating decimal
numbers. A nonterminating decimal number has infinitely many nonzero
digits following the decimal point. For example, 0.333333333 .. . is a non-
terminating decimal number. Some nonterminating decimal numbers re-
1
present fractions—0:333333333 .. . ¼ . But some nonterminating
3 p ffiffiffi
decimals, like ¼ 3:1415926654 .. . and 2 ¼ 1:414213562 .. ., do not rep-
resent fractions. We will be concerned mostly with terminating decimal
numbers in this book.
You can add as many zeros at the end of a terminating decimal number as
you want because the extra zeros cancel away.
7
0:7 ¼
10
70 7 10 7
0:70 ¼ ¼ ¼
100 10 10 10
700 7 100 7
0:700 ¼ ¼ ¼
1000 10 100 10

Adding and Subtracting Decimal Numbers

In order to add or subtract decimal numbers, each number needs to have the
same number of digits behind the decimal point. If you write the problem