Divide your number by prime numbers, making a list of each factor you divide it by. Start by dividing the number by two until it can no longer be divided by two. Divide the number by three (the next largest prime number). Continue to divide the number by increasingly larger prime numbers until all you are left with is a prime number. For example, 24 divided by two is 12; 12 divided by two is six; six divided by two is three. The prime factors of 24 are two, two, two and three.
Multiply the number's prime factors by each other in every possible combination. A number's composite factors are found when multiplying two or more prime number factors together. The composite factors of 24 are four (2 x 2), six (2 x 3), eight (2 x 2 x 2) and 12 (2 x 2 x 3). If you look at the example in the first step, many of the composite factors were found when finding the prime factors, but they aren't always all identified this way. The number eight is a composite factor of 24, but was not found in the first example.
Figure out how to divide something equally. If six people worked together to make brownies, and the pan of brownies yields 24 brownies, it would only be fair if everyone received the same number of brownies. Because six is a factor of 24, the brownies can be evenly divided into equal shares without cutting them into smaller pieces. Dividing 24 by six gives a result of four. Each person gets four brownies.
Using money is a common way we use factors without realizing it. Everyone knows that four quarters make a dollar. Looking at it in terms of factors, two factors of 100 are four and 25. A twenty-dollar bill can be exchanged for twenty one-dollar bills (factors one and 20), two ten-dollar bills (factors two and 10) or four five-dollar bills (factors four and five).
Compare prices using factors. There are two cans of an expensive coffee blend on sale. A 12-ounce can costs $36.00. A six-ounce can costs $24.00. Using factors, the price per ounce can be compared without the use of a calculator or notepad. Dividing 36 by 12, the factors of 36 are three and 12. Dividing 24 by six, the factors of 24 are four and six. Using this information, we learn that the 12-ounce can costs $3.00 per ounce and the six-ounce can costs $4.00 an ounce.
Time is divided into factors. Every day has 24 hours; if you have to take a pill three times a day, you take one every eight hours (3 x 8 = 24). An hour is divided into 60 minutes. Those 60 minutes are divided into 12 increments of five minutes each on the face of a clock (12 x 5 = 60). Hours are often divided into quarter- (4 x 15 = 60) and half-hour (2 x 30 = 60) segments.
Factors are used when traveling. If you're taking a 720-mile trip, you need to know how many hours you'll be driving, so you can plan your trip. At an average speed of 60 mph, it would take 12 hours to get to your destination (60 x 12 = 720).