math help

What is 25/15 + 1/4?

What is 25/15 + 1/4?

This is how we add

25
15
+
1
4

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 25 by 4, and get 100, then we multiply 15 by 4 and get 60.

25/15 times 4

Now for the second term. You multiply 1 by 15, and get 15, then multiply 15 by 4 and get 60.

1/4 times 15

This gives us a new problem that looks like so:

100
60
+
15
60

Step 2

Since our denominators match, we can add the numerators.

100 + 15 = 115

So what's the answer so far?

115
60

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

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

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:

115
60
÷ 5 =
23
12

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

No good. 13 is larger than 12. So we're done reducing.

There you have it! Here's the final answer to 25/15 + 1/4

25
15
+
1
4
=
23
12
© 2014 Randy Tayler