Anyone Good At Math?

[Insanity]

Textbooks and sites confuse me, no idea why. Anyone mind helping me brush up on math, such as division, percentages, and fractions? And angles too? x.o

As far as GED prep goes, this is my only major weak point.

 

[Veritas et Lux]

lol what do you need help on?

I'm taking algebra 2 honors right nao

 

[Insanity]

Fractions. :( But mostly percentages and division. Been so long since I took classes. ><

 

[Santoro]

Fractions. :( But mostly percentages and division. Been so long since I took classes. ><

It's how the rest of the world does math.

 

[Insanity]

Can't use calculators when taking the math portion of the GED... :(

 

[Cyril Khan]

I'd have to hear a few examples of what you need help with. For me, fractions, division, and percentages can mean anything.

 

[Insanity]

*Random responses are random*

For percentages, basically how you'd figure out what taxes are for a price or how to figure out what, say, 10% of 113 would be.

As for fractions, figured out that bit mostly.

And division would be that I seem to have forgotten how you divide a number by another number. ._.

 

[Cailst]

What sort of division do you want to know? There's long division where you write everything out and then there's short division which is shorter.

And what exactly do you want to know about percentages and angles?

 

[Insanity]

Anything that'd be helpful on the math portion of the GED test... ^^; Since half of it won't let you use a calculator.

 

[Andreus Makaryk]

*Random responses are random*

For percentages, basically how you'd figure out what taxes are for a price or how to figure out what, say, 10% of 113 would be.

As for fractions, figured out that bit mostly.

And division would be that I seem to have forgotten how you divide a number by another number. ._.

Percentages are hundredths of something. So to calculate a percentage of something, you multiply that something by what that percentage would be as expressed by a decimal--i.e. two decimal places to the left.

In the example you gave, you would do this: 113*.10=11.3

It is possible to get a value greater than 1 to multiply by for certain problems, for example, 250% would become 2.50.

Note that technically the .10 could be shortened to .1 because the zero is a placeholder (unless you're working with science and the zero was part of a measured value, i.e. measured to two places in this case, that would be called "significant digits"). If you are working with a word problem involving currency, the answer might get expressed as $11.30 instead of 11.3.

If it's one of those "figure the TOTAL cost of the item after sales tax" questions, you'd have to add the value you calculated for sales tax back on to the original price, to get a total price of $124.30.

Read word problems carefully and logically to see what they require! Hope that helps. :)

 

[Cyril Khan]

There are tips to mental percentage calculation. When dealing with percentages from 1 to 9%, you can just multiply the number by the percentage and divide by 100.

i.e. 4% of 235: 235 x 4 = 930, 930/100 = 9.3

Any percentages that are put in tens can be done the same way, but you multiply by the tens digit and divide by 10.

i.e. 10% of 113: 113 x 1 = 113, 113/10 = 11.3
i.e. 70% of 162: 162 x 7 = 1134, 1134/10 = 113.4

Also, 10% of anything is that number divided by 10. SO... 20% of any number is twice that much, 5% of any number is half that much. 30% is three times as much, 40% is four times that much, and so on.

i.e. 20% of 113: 113/10 = 11.3, 11.3 x 2 = 22.6
i.e 5% of 113: 113/10 = 11.3, 11.3/2 = 5.65
i.e 2000% of 113: 113/10 = 11.3, 11.3 x 200 = 2260

Division isn't something I'm good at explaining even if I had paper to show you in person. I either use a calculator for it, or I just do it in my head. On any test or project where I am not allowed to use a calculator, I only use exact answers, so long division never comes up.

I do have a tip if you think you can handle it. It is always easier to do division if you simplify both terms (this is what I have to do when giving an exact answer).

Take 204 divided by 26. By dividing both numbers by 2, you can reduce them to 102 divided by 13.

Take 648 divided by 208. By dividing both numbers by 2, you can reduce them to 324 divided by 104. You can still divide those numbers by 2, and if you do so you get 162 divided by 51.

Note: I did not use a calculator when I did any of this. Any mistakes are in my own calculations and not in my formulas.

 

[Endling vas Precious]

I can't math.