Is this a tricky Question?

woenlee · 2012-05-28 13:02:16

I was taught to solve math in the order Multiplication then Division follow with Addition then Subtraction.

So what is the answer to (7-6+4)=?

was it 5 or -3 ?

Why?

bobbym · 2012-05-28 13:12:20

Hi woenlee;

This can be a little tricky.

I used PEMDAS. This is fine as long as you remember that Multiplication and Division have the same precedence and so do Addition and Subtraction.

They are taught today to think of 7 - 6 + 4 as

7 + (-6) + 4 which simplifies the order of operations. You now have 2 additions. You take these on a first come basis:

7 + (-6) = 1

1 + 4 = 5

The answer is 5

Luckily there is a trick if you ever get confused. You can ask the best mathematician you are ever likely to know. Your computer!

First you could enter 7-6+4 right into google and press enter and google would give you the answer of 5.

Second you could go here,

enter 7-6+4 into the top line and click the equals and get 5.

Third, you can go here,

enter 7-6+4 click equals and get 5.

Bob · 2012-05-28 19:18:44

hi woenlee

Welcome to the forum!

Multiplication then Division follow with Addition then Subtraction.

This is not correct.

In the absence of any brackets, multiplication and division should be taken in the order they arise, and similarly adition and subtraction.

So 8 / 2 x 4 = (8/2) x 4 = 4 x 4 = 16

If you want to say 8 / (2 x 4) you must use brackets.

And 7 - 6 + 4 = (7 - 6) + 4 = 1 + 4 = 5

Again brackets are necessary to change to 7 - (6 + 4) = 7 - 10 = -3

Have a look at

Bob

Math Is Fun Forum