math help

What is 78/92 + 3/7?

What is 78/92 + 3/7?

Here's how you add

78
92
+
3
7

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 78 by 7, and get 546, then we multiply 92 by 7 and get 644.

78/92 times 7

Do the same for the second term. We multiply 3 by 92, and get 276, then multiply 92 by 7 and get 644.

3/7 times 92

So now our fractions look like this:

546
644
+
276
644

Step 2

Since our denominators match, we can add the numerators.

546 + 276 = 822

Now we have an answer.

822
644

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:

822
644
÷ 2 =
411
322

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...

Nope! So now we try the next greatest prime number, 53...

Nope! So now we try the next greatest prime number, 59...

Nope! So now we try the next greatest prime number, 61...

Nope! So now we try the next greatest prime number, 67...

Nope! So now we try the next greatest prime number, 71...

Nope! So now we try the next greatest prime number, 73...

Nope! So now we try the next greatest prime number, 79...

Nope! So now we try the next greatest prime number, 83...

Nope! So now we try the next greatest prime number, 89...

Nope! So now we try the next greatest prime number, 97...

Nope! So now we try the next greatest prime number, 101...

Nope! So now we try the next greatest prime number, 103...

Nope! So now we try the next greatest prime number, 107...

Nope! So now we try the next greatest prime number, 109...

Nope! So now we try the next greatest prime number, 113...

Nope! So now we try the next greatest prime number, 127...

Nope! So now we try the next greatest prime number, 131...

Nope! So now we try the next greatest prime number, 137...

Nope! So now we try the next greatest prime number, 139...

Nope! So now we try the next greatest prime number, 149...

Nope! So now we try the next greatest prime number, 151...

Nope! So now we try the next greatest prime number, 157...

Nope! So now we try the next greatest prime number, 163...

Nope! So now we try the next greatest prime number, 167...

Nope! So now we try the next greatest prime number, 173...

Nope! So now we try the next greatest prime number, 179...

Nope! So now we try the next greatest prime number, 181...

Nope! So now we try the next greatest prime number, 191...

Nope! So now we try the next greatest prime number, 193...

Nope! So now we try the next greatest prime number, 197...

Nope! So now we try the next greatest prime number, 199...

Nope! So now we try the next greatest prime number, 211...

Nope! So now we try the next greatest prime number, 223...

Nope! So now we try the next greatest prime number, 227...

Nope! So now we try the next greatest prime number, 229...

Nope! So now we try the next greatest prime number, 233...

Nope! So now we try the next greatest prime number, 239...

Nope! So now we try the next greatest prime number, 241...

Nope! So now we try the next greatest prime number, 251...

Nope! So now we try the next greatest prime number, 257...

Nope! So now we try the next greatest prime number, 263...

Nope! So now we try the next greatest prime number, 269...

Nope! So now we try the next greatest prime number, 271...

Nope! So now we try the next greatest prime number, 277...

Nope! So now we try the next greatest prime number, 281...

Nope! So now we try the next greatest prime number, 283...

Nope! So now we try the next greatest prime number, 293...

Nope! So now we try the next greatest prime number, 307...

Nope! So now we try the next greatest prime number, 311...

Nope! So now we try the next greatest prime number, 313...

Nope! So now we try the next greatest prime number, 317...

Nope! So now we try the next greatest prime number, 331...

No good. 331 is larger than 322. So we're done reducing.

There you have it! Here's the final answer to 78/92 + 3/7

78
92
+
3
7
=
411
322
© 2014 Randy Tayler