In fraction form, 2.5 is 5/2. First the decimal portion (0.5) must be calculated. The value of the decimal (5) is put over the place value (10ths) of the decimal (5/10), which is reduced to equal 1/2. Next, the whole number (2) is multiplied by the denominator (2 * 2 = 4), and this number is added to the numerator (4 + 1 = 5) to determine the final answer, 5/2.
When putting a number into a fraction, it can be helpful to think of it in terms of pies. In the following example, Sally has been tasked with splitting 2.5 available pies up equally among a group of five people. A single serving is one-half of a pie. From working with the decimal portion of the fraction, Sally determined half of a pie (1/2) was available in addition to the two whole pies. Next, Sally must determine how many servings are available from the two whole pies to ensure there’s enough for everyone. Sally multiplied the whole numbers by the denominator (bottom half of the fraction) to determine how many half-pie pieces are available in both of those whole pies, and then added it to the numerator (top half of the fraction) to calculate how many half-pie pieces there are altogether. Sally calculated that two whole pies have four half-pie pieces in total. Adding in the last pie piece, Sally found the total number of half-pie pieces to be five (5/2), which is enough for everyone.