Multiply every different denominator together. For example, if you are comparing 2/3, 5/6, and 1/3, multiply the two different denominators: 3 x 6 = 18. This is a simple method, but will often result in a much larger number than the other methods, which can be difficult to work with. [2] X Expert Source David JiaAcademic Tutor Expert Interview. 23 February 2021 Or list the multiples of each denominator in a separate column, until you notice a number that shows up on every column. Use this number. For example, comparing 2/3, 5/6, and 1/3, list a few multiples of 3: 3, 6, 9, 12, 15, 18. Then list the multiples of 6: 6, 12, 18. Since 18 shows up on both lists, use that number. (You could also use 12, but the examples below will assume you are using 18. )
18 ÷ 3 = 6, so 2/3 = (2x6)/(3x6)=12/18 18 ÷ 6 = 3, so 5/6 = (5x3)/(6x3)=15/18 18 ÷ 3 = 6, so 1/3 = (1x6)/(3x6)=6/18
6/18 = (6 ÷ 6)/(18 ÷ 6) = 1/3 12/18 = (12 ÷ 6)/(18 ÷ 6) = 2/3 15/18 = (15 ÷ 3)/(18 ÷ 3) = 5/6 The answer is “1/3, 2/3, 5/6”
This method is called cross-multiplication, because you multiply numbers in a diagonal line across from each other.
This method is called cross-multiplication, because you multiply numbers in a diagonal line across from each other.
This method is called cross-multiplication, because you multiply numbers in a diagonal line across from each other.
Remember, always write the cross-product next to the fraction whose top number you used.
3/5=(3x3)/(5x3)=9/15 2/3=(2x5)/(3x5)=10/15 9/15 is less than 10/15 Therefore, 3/5 is less than 2/3
You can still use the other methods for these fractions. This method helps these fractions make sense, however, and might be faster.
1 is the smallest 2 + 2/3 and 2 + 1/6 (we don’t yet know which is larger than the other) 4 + 3/4 is the largest
2/3 = (2x2)/(3x2) = 4/6 1/6 = 1/6 4/6 is greater than 1/6 2 + 4/6 is greater than 2 + 1/6 2 + 2/3 is greater than 2 + 1/6
