Lesson 22 Section 2 CLEARING A FRACTION OF DECIMALS |
|||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||
That is called clearing of decimals.
Solution. To reduce a fraction, both the numerator and denominator must be whole numbers. To make 1.5 into the whole number 15, multiply it by 10. (Lesson 4, Question 2.) Multiply 2 by 10 also:
15 and 20 have a common divisor 5.
1.5 is to 2 as 3 is to 4. Therefore, if we ask, "What ratio has 1.5 to 2?", we can answer 1.5 is three fourths of 2.
Solution. To decide by which power of 10 to multiply, look at the number with the most number of decimal digits; in this case, .004. Therefore we will multiply both numbers by 1000:
4 goes into 200 fifty times. As for the ratio of .2 to .004, it is the same as 200 to 4, or 50 to 1. .2 is fifty times .004. We discover this important fact:
Example 3. What ratio has .07 to 1.4? Answer. Clear of decimals. Multiply both numbers by 100:
.07 is to 1.4 as 1 is to 20. .07 is the twentieth part of 1.4. Example 4. $6.30 has what ratio to $8.40? $6.30 is what percent of $8.40?
Please "turn" the page and do some Problems. or Continue on to the next Lesson. Introduction | Home | Table of Contents Copyright © 2017 Lawrence Spector Questions or comments? E-mail: themathpage@yandex.com Private tutoring available. |