OMG GUYS I NEED HELP!!!!!!!
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mhmm…
Yall im creating a discussion just for math now
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Yo you gotta study or smth BRO
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i am in a math class called Technical Math. and we do all kinds of math problems but thee only catch is that we're not allowed to use a cacalator for the entire semester. but here is one of the problems that i had missed:
0.1 divided by 0.0805
How Does Anyone Do This Without A Calcalator!
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(The □ are because spaces disappear if you put over one and if there's not enough spacing this would be hard to read. Ignore them.)
First, turn it into fractions because fractions are much easier to deal with than decimals.
1 □□ 805
— □÷ ———
10 □ 10,000
Then, to divide fractions, flip the second one and turn the ÷ into an ×. So;
1□□□10,000
— □ × ———
10 □□ 805
And then, multiply.
10,000
————
8050
And finally, simplify, by dividing both sides by the same number at once until you can't make it get any simpler.
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Division with decimals is easy because it's powers of 10. You divide like you normally would but then move the decimal place based on what you're dividing by. So treat. 0.805 like you're dividing by 1. Your result would be .805 right? You then move the decimal place to the left or right depending on what value you were dividing by. Since you were dividing by 0.1 or 10^-1(because 0.1 is 10^-1 or negative 1), move the decimal to the right to get 8.05.
To divide decimals, make the number you are dividing by (the divisor) a whole number by moving its decimal point to the right, and move the decimal point in the number being divided (the dividend) the exact same number of places.
Above is from a simple search so applying that in practice is 0.1 → 1 x 10^-1 because that's what it actually is. Whenever you move decimals to the right, the exponent becomes negative or smaller while moving the decimal to the left it becomes larger. So 3000 is 3 x 10^3(decimal is hiding by the 0).
Another way to apply it is to convert things into two products or (8.05 x 10^-1) ÷ (1 x 10^-1). Whenever you have two numbers raised to the same exponent(in this case base 10), you take the two coefficients or 8.05 and 1 and apply it as you normally would. 8.05 ÷ 1 = 8.05. Then you take the Exponent part and 10^-1 ÷ 10^-1 is really interesting because whenever you divide by an exponent, you can change it to multiplication by changing the value of the divisor from negative to positive so it becomes 10^-1 x 10^1. Whenever you multiply exponents, you add so -1 + 1 = 0. Anything raised to the 0 power is 1. So the answer is 8.05. If you do your thing on a calculator, you'll see I'm right.
PS: What I did here is something Chemistry Teachers have you do(at least good ones). If I took 25 million(2.5 x 10^7) and divided by 50(5 x10^1) id get 2.5 /5 = 0.5 x 10^7-1 or 0.5 x 10^6. Then shift the coefficient to the right, getting a smaller exponent or 5 x 10^5 or 500,000. Am I right? Answer is yes.
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You misread the question. It's 0.1÷0.0805, not 0.805÷0.1.
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Ah well same thing applies. (100 × 10^-3) ÷ (805 × 10^-4). 100/805 is 4th grade math but comes out to roughly 0.124(and more of you keep expanding it out) x 10^-3 ÷ 10^-4. Whenever you divide you subtract exponents or -3 - (-4) or -3 + 4 = 1. In other words it's whatever 100/805 comes out to or roughly 0.124 x 10^1 or 1.24 worked all the way out
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@Lonestar85 @UnovanZorua I wish i was as good as yall!
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Not that hard. All you got to do is convert things by moving the decimal place. Whenever you do your effectively multiplication by base 10. The vale of base 10 goes up when you move left and goes down when you move right. So 25000 → 2.5 x 10^4. Mathematically they're the same.
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