Step-by-step explanation: To write a percent as a fraction in lowest terms, remember that a percent is a ratio that compares a number to 100. In this case, 90% can be written as the ratio 90 to 100 of 90/100. Notice that 90/100 is not in lowest terms so we need to divide the numerator and denominator by the greatest common factor of 90 and 100 which is 10.
90 ÷ 10 = 9
100 ÷ 10 = 10
Therefore, 90% can be written as the fraction 9/10 which is in lowest terms.
