math help

What is 99/7 + 4/10?

What is 99/7 + 4/10?

Let's add

99
7
+
4
10

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 99 by 10, and get 990, then we multiply 7 by 10 and get 70.

99/7 times 10

Do the same for the second term. We multiply 4 by 7, and get 28, then multiply 7 by 10 and get 70.

4/10 times 7

So now our fractions look like this:

990
70
+
28
70

Step 2

Since our denominators match, we can add the numerators.

990 + 28 = 1018

So the answer is:

1018
70

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:

1018
70
÷ 2 =
509
35

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...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

No good. 37 is larger than 35. So we're done reducing.

There you have it! Here's the final answer to 99/7 + 4/10

99
7
+
4
10
=
509
35
© 2014 Randy Tayler