Page 23 - CalcBus_Flipbook

CH 3] Calculating Business 3-7

In Example 3, the numerator is 3/4, which is 3 ÷ 4, and arithmetically yields the equivalent
decimal value of 0.75. The arithmetic for this number is the same as in Example 1 and 3
discussion for denominators.

4
Example A: is a complex fraction. The numerator is 4 and the denominator is 1/4.
1/4

4 4
Solution: = = 16 Denominator is first, numerator is second.
1/4 0.25

2/5
Example B: is a complex fraction. The numerator is 2/5 and the denominator is 4.
4

2/5 2/5 0.4
Solution: = = = 0.10 Denominator is first, numerator is second. 3
4 4 4

3/4
Example C: is a complex fraction. The numerator is 3/4 and the denominator is 9/10.
9/10

3/4 3/4 0.75
Solution: = = = 0.8333 Denominator is first, numerator is second.
9/10 0.90 0.90

Solution C: With your hand calculator, in this order, denominator first and then numerator:

Cl/C 9 ÷ 10 = M+ 3 ÷ 4 = ÷ MR = 0.8333

Denominator Numerator Answer

Understanding the order for complex fractions is important when calculating compound interest,
annuity values, and determining the monthly payment on a loan.

Rounding Decimal Fractions. The rules commonly used to round decimal fractions are
delineated in Figure 3.5 :

1. Here's the general rule for rounding: If the number you are rounding is followed
by 5, 6, 7, 8, or 9, round the number up. Example: 38 rounded to the nearest ten is
40. If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number
down. Example: 33 rounded to the nearest ten is 30.
2. Determine the rounding point: one decimal place, two decimal places, three decimals
places, which are 1/10, 1/100, 1/1000. Underline the digit in the place specified. This is the
place digit.
3. The first digit to the right of the place digit is the test digit.
4. If the test digit is in the number range of 5, 6, 7, 8, or 9, add 1 to the place digit. (Rounding
up)
5. If the test digit is in the number range of 0, 1, 2, 3, or 4 do not change the place digit.
(Rounding down)

Figure 3.5 Rules for Rounding
Copyrighted Material