math help

What is 10/12 + 7/10?

What is 10/12 + 7/10?

Here's how we add

10
12
+
7
10

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 10 by 10, and get 100, then we multiply 12 by 10 and get 120.

10/12 times 10

Now for the second term. You multiply 7 by 12, and get 84, then multiply 12 by 10 and get 120.

7/10 times 12

We now have a new problem, that looks like this:

100
120
+
84
120

Step 2

Since our denominators match, we can add the numerators.

100 + 84 = 184

That gives us the sum, which is

184
120

Step 3

Now, do we need to simplify this fraction?

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

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

184
120
÷ 2 =
92
60

Let's try dividing by that again...

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

92
60
÷ 2 =
46
30

Let's try dividing by that again...

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

46
30
÷ 2 =
23
15

Let's try dividing by that again...

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

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

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...

Nope! So now we try the next greatest prime number, 17...

No good. 17 is larger than 15. So we're done reducing.

There you have it! Here's the final answer to 10/12 + 7/10

10
12
+
7
10
=
23
15
© 2014 Randy Tayler