math help

What is 25/15 + 2/6?

What is 25/15 + 2/6?

This is how to add

25
15
+
2
6

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 25 by 6, and get 150, then we multiply 15 by 6 and get 90.

25/15 times 6

Do the same for the second term. We multiply 2 by 15, and get 30, then multiply 15 by 6 and get 90.

2/6 times 15

So now our fractions look like this:

150
90
+
30
90

Step 2

Since our denominators match, we can add the numerators.

150 + 30 = 180

So the answer is:

180
90

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

180
90
÷ 2 =
90
45

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

90
45
÷ 3 =
30
15

Let's try dividing by that again...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

30
15
÷ 3 =
10
5

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

10
5
÷ 5 =
2
1

Let's try dividing by that again...

No good. 5 is larger than 2. So we're done reducing.

There you have it! Here's the final answer to 25/15 + 2/6

25
15
+
2
6
=
2
1
= 2
© 2014 Randy Tayler