Examine the first denominator, 5, in the expression 4/5 x 10/16. Notice the adjacent numerator 10. Five is a common factor of both 5 and 10. This shows how the adjacent numerator affects the denominator, resulting in a cancellation.
Divide the first denominator by 5. Cross out the denominator and write the remainder in its place. After the denominator cancels out, the fraction is 4/1. This example shows how a denominator will cancel out to the understood one.
Divide the 10 numerator by 5, cross out the numerator and write the remainder in its place. After factoring out the greatest common factor, the expression 4/1 x 2/16 remains. However, notice the second denominator, 16. Both it and the first numerator have a GCF of 4.
Divide the numerator by the GCF and write the remainder in its place: 1/1. Divide the denominator by the GCF 4 and write the remainder in its place: 2/4. Now the expression reads 1/1 x 2/4. This is an example of how only a part of a denominator will cancel.
Examine the second fraction: 2/4. Both parts of the fraction have a common factor of 2. This is an example of using the numerator of a fraction to cancel out the denominator of the same fraction.
Divide both parts of the fraction by the GCF, crossing out the current values and writing the remainders in their places. Therefore, 2/4 becomes 1/2.
Simplify the expression 1/1 x 1/2. Remember that fractions represent parts and wholes, so the fraction 1/1 simplifies to 1. You may also look at it as a division problem, in which case, any number divided by one equals one. After simplifying, the expression reads 1 x 1/2 = 1/2.