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View Full Version : Divide 30 by half And add 10 . What you will get?


dragonsalu161
Mar 27, 2011, 05:16 AM

Curlyben
Mar 27, 2011, 05:18 AM
A lot more than you initially think..

What happens when you DIVIDE by a fraction ?

jcaron2
Mar 27, 2011, 06:57 AM
Let's do this one step at a time. I know you can do the second step, so we'll start with the first.

What's 30 divided by 1/2? Let's start with a real-life example where you can do this division in your head: If it costs 50 cents (1/2 of a dollar) to buy a can of soda, how many cans can you buy with 30 dollars?

Now the "mathematical" way to do this: Remember that division is the same thing as "multiplication by the reciprocal". That phrase simply means that you take the divisor (the thing that you're dividing by) and you "flip it over" as a fraction, then multiply instead of divide. So division by 1/2 becomes multiplication by 2/1 (which is the same as plain ol' 2). Likewise, division by 5/7 is the same as multiplication by 7/5; division by 14 (which is the same as 14/1) is the same as multiplication by 1/14.

So 30 divided by 1/2 is the same as 30 multiplied by 2. What does that equal?

Now just add 10 to your answer.

eawoodall
Apr 3, 2011, 06:00 PM
Exaple:
You have 30 pizzas, they cut them in half,
Then they give you ten slices of the same size free because you bought so much pizza.

How many slices of pizza do you have?

30 / (1/2) + 10
Note :division is invert and multiply equivalent
30(2/1) + 10
60/1 + 10
60 + 10
70.