math help

What is 25/9 + 8/10?

What is 25/9 + 8/10?

This is how we add

25
9
+
8
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 25 by 10, and get 250, then we multiply 9 by 10 and get 90.

25/9 times 10

Do the same for the second term. We multiply 8 by 9, and get 72, then multiply 9 by 10 and get 90.

8/10 times 9

So now our fractions look like this:

250
90
+
72
90

Step 2

Since our denominators match, we can add the numerators.

250 + 72 = 322

Now we have an answer.

322
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:

322
90
÷ 2 =
161
45

Now, try the same number again.

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

No good. 47 is larger than 45. So we're done reducing.

Congratulations! Here's your final answer to 25/9 + 8/10

25
9
+
8
10
=
161
45
© 2014 Randy Tayler