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8    ARMY AIR FORCES

(5) .890625=?
(6) 3.828125=?    3 53/64 Answer.
(7) 6.25=?
(8) 4.375=?   4 3/8 Answer. 
(9) 1.6875=?
(10) 2.3125=?    2 5/16 Answer.

e. Percentage. - Percent means a number with an understood denominator of 100. For example, 50 percent (%) means 50/100 or .50.

(1) To change from percent to decimal, divide the number of percent by 100, which is equivalent to moving the decimal point two places to the left, and omit "percent."

(a) Example: Change 42 percent to a decimal.
Solution: 42 percent=42/100=.42    Answer.
(b) Example: Change .9 percent to a decimal. Answer.
Solution: .9 percent = .9/100=.009
(c) Example: Change 1/2% to a decimal.
Solution: 1/2% = .5%=.5/100=.005 Answer.
(2)To change from a decimal to a percent, multiply the decimal fraction by 100, which is equivalent to moving the decimal point two places to the right, and add "percent" (or "%") 
(a)Example: Express .45 as a percent.      Answer.
Solution:.45X100=647 percent 
(b)Example: Express 6.47 as a percent.
Solution: 6.47X100 = 647 percent      Answer.
(c)Example: Express .0048 as a percent.
Solution:.0048X100 = .48%  Answer.
(3)It is common to specify changes in troop strength, population, enlistments, and even changes in the physical dimensions of pistons, for example, in terms of percent. The following examples illustrate the methods of solving this type of problem:
(a)Example: If the population of the United Stated was 120,000,000 un 1930 and increased 7 percent during that year, what was it in 1931?
Solution: 7 percent = .07 
.07X120,000,000=8,400,000.
Therefore the population in 1931 was 120,000,000+8,400,000=128,400,000
(b)Example: At a certain altitude and temperature, the true air

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