Well, when you have a problem with so:
3 3/4- 2 2/3
You can subtract that. The fractions don't have an equal denominator. Equivalent fractions can help us subtract these fractions to get an equal number without it being too complicated to do.
Both can be equivalent to a fraction of 12.
3/4= 9/12 2/3= 8/12
Now, we can subtract them. But we needed to rename the fractions with different denominators.
3 9/12- 2 8/12= 1 1/12
See? It makes it much simpler.
I hope this helps!
~kaikers
