math help

What is 100/72 + 7/10?

What is 100/72 + 7/10?

Here's how to add

100
72
+
7
10

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 100 by 10, and get 1000, then we multiply 72 by 10 and get 720.

100/72 times 10

Now for the second term. You multiply 7 by 72, and get 504, then multiply 72 by 10 and get 720.

7/10 times 72

This gives us a new problem that looks like so:

1000
720
+
504
720

Step 2

Since our denominators match, we can add the numerators.

1000 + 504 = 1504

So what's the answer so far?

1504
720

Step 3

Can this fraction be reduced?

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

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

1504
720
÷ 2 =
752
360

Let's try dividing by that again...

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

752
360
÷ 2 =
376
180

Let's try dividing by that again...

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

376
180
÷ 2 =
188
90

Let's try dividing by that again...

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

188
90
÷ 2 =
94
45

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...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

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

There you have it! Here's the final answer to 100/72 + 7/10

100
72
+
7
10
=
94
45
© 2014 Randy Tayler