Tham khảo tài liệu 'the gre anlytycal writting section 5', ngoại ngữ, anh ngữ phổ thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | --------------------- THE GRE QUANTITATIVE SECTION --------- Operations with Decimals To add and subtract decimals you must always remember to line up the decimal points .333 - To multiply decimals it is not necessary to align decimal points. Simply perform the multiplication as if there were no decimal point. Then to determine the placement of the decimal point in the answer count the numbers located to the right of the decimal point in the decimals being multiplied. The total numbers to the right of the decimal point in the original problem is the number of places the decimal point is moved in the product. For example 2 2 1 x 36 w TOTAL s TO THE RIGHT OF 7 4 0 4 the decimal point 4 6 1 7 0 0 63134 4 3 2 1 To divide a decimal by another such as or move the decimal point in the divisor to the right until the divisor becomes a whole number. Next move the decimal point in the dividend the same number of places 245 This process results in the correct position of the decimal point in the quotient. The problem can now be solved by performing simple long division 245 -1225 166 6 -1470 1960 Percents A percent is a measure of a part to a whole with the whole being equal to 100. To change a decimal to a percentage move the decimal point two units to the right and add a percentage symbol. 160 THE GRE QUANTITATIVE SECTION Examples .45 45 .07 7 .9 90 To change a fraction to a percentage first change the fraction to a decimal. To do this divide the numerator by the denominator. Then change the decimal to a percentage by moving the decimal two places to the right. Examples 5 .80 80 ị .4 40 I .125 To change a percentage to a decimal simply move the decimal point two places to the left and eliminate the percentage symbol. Examples 64 .64 87 .87 7 .07 To change a percentage to a fraction divide by 100 and reduce. Examples 64 16 75 3 82 41 64 100 25 75 100 4 82 100 50 Keep in .
