In a fish tank 2/10 of the fish were orange and 5/100 of the fish were stripped. what fraction of the fish were orange or stripped

Let's first start off by making 2/10 the same denominator as 5/100. To do this you would need to multiply both sides of the fraction by 10. You wild end up with 20/100. Now we worry about the striped fish. There are 5/100 striped fish, since we have the same denominator we can add them together! 20+5=25 25/100 is reduced to 1/4!

You need to get them both over the same denominator

so 2/10 = 20/100

20/100 + 5/100 = 25/100

25/100 = 1/4