Math question

Just to make sure Im right on this one. 60% of 170 is 102 right?

 

yes

 

you cross multiply.

n 60
__ = ___ =====> 60*170=x. and then divide x by 100

170 100

 

Wouldn't just 170 * .6 be quicker?

 

Yes, it would be quicker, and simpler. If you want to find the percent of a number to a number, just multiply by a number like .1(10%) or .4(40%) to find what you are looking for.

 

unless you have 3/7 of 490, then it would be easier to cross multiply

 

press the windows key+R

type, calc

 

the easiest way to do that is when you see some percent OF some number (of means multiply) EQUALS that means the answer...

that the percent and for 60 its .60 OF is times so times 170 IS 102

aka

.60(170)=102

if you have a piece of information missing, you can still find it the same way- just algebracially.

 

No way cross multiplying sux everytime

 

not at all. if you simplify the equation, it is simple to cross multiply. take the denominator of 3/7 which is 7 and divide by 7 which makes it 1. then you can divide 490 by 7, which makes that number 70. so you have 3/1 times 70/1 which is basically 3 times 70, which equals 210. which is a hell of a lot easier than finding a percentage of 3/7 and multiplying it by 490.

 

they dont allow cross mulitipling in my class...think it's a "child's" way to deal with it. then again, it is algebra.

 

thats how I did it

490/7 = 70*3 = 210

 

My teacher got mad cause while he was showing everyone how to use crossX to do it I was just finishing up. I think he couldn't understand my work if I didn't.

 

i still think my way is more simple.

start with the percent... make it into a decimal- times it by the OF and the IS is after the equal sign.

get out the calculator... simple.

 

170*60=10200 then take tha last to places off, much quicker

 

naw, its easier to simplify the equation first and do it in your head.

 

I did do it in my head it's easy cause 49 is a multiple of 7

 

well, is that any more simple?

it would take me 5 seconds to do it my way.

i guess it's what your most comfortable with.

 

then again, im more used to doing them in alg. class where there is a variable so you guys might be right for this problem.

 

Just do it all in your head, that's the best way. And if your instructor can't understand how you figured it out, all the better, 'twas probably more efficient.