Maths - Common Denominator

LI: To find the common denominator between fractions.

The common denominator is the highest denominator between multiple fractions. To find the most common denominator between fractions, identify the largest denominator and find out how to multiply the other fractions to equal the largest denominator.

First, take a fraction such as 2/3 and 5/9, the largest denominator between the two is 9, so we have to find out how to make sure the denominator of 2/3 is a 9. By using our knowledge, we know that 3x3 is 9, so the denominator becomes 9. However, then we have to multiply the numerator. 2x3=6, therefore the fractions are 6/9 and 5/9.

We practiced finding out highest common denominator between fractions by using our prior knowledge of timestables and multiplication.

I enjoyed this maths lesson because I was able to apply my knowledge of timestables, multiplication and place value to uncover the highest common denominators of fractions.