Computers and calculators make division quick and painless, but they aren't always around when you need them. Instead of relying on a machine to crunch your numbers, arm yourself with the old-fashioned way of dividing numbers, namely long division. For complex problems, you'll probably need a pen and paper, but after following a simple procedure, you'll be solving complex division without batting an eye.
Write the divisor on the left side of the division bracket and the dividend under the bracket's horizontal bar. The divisor is the number you are dividing into the dividend. As an example, you might write "1.2" on the left and "34" under the horizontal bar.
Move the divisor's decimal point to the right of the last nonzero digit and move the dividend's decimal point the same number of places. In the example, the divisor changes to 12, and the dividend changes to 340.
Calculate how many times the divisor will go into the first digit of the dividend. This might require trial and error. If the dividend's first digit is larger than the divisor, use the first two digits, and so on. Write this number over the division bracket's horizontal bar, just over the last digit you used in the dividend. In the example, 12 won't go into 3, but it'll go into 34 two times, so you write "2" over the last digit of 34. This number is the first digit of the resulting quotient.
Multiply the number you just wrote by the divisor and enter it below the portion of the dividend you used in the calculation. In the example, 2 times 12 produces 24, so write "24" under 34.
Subtract the two figures to derive the remainder and drop down the next digit of the dividend. In the example, 34 minus 24 leaves you with 10. Dropping down the zero gives you a new figure of 100.
Continue the procedure of calculating the number of times the divisor goes into the next number, writing this number above the horizontal line, multiplying by the divisor and subtracting the two numbers. When there's no more numbers left in the dividend, whatever is left is the remainder. In the example, the 12 goes into 100 eight times, so write "8" to the right of the 2 above the horizontal line. Multiply 8 by 12 gives to get 96 and subtract 96 from 100 to get a remainder of 4. This gives you a quotient as 28 with a remainder of 4. You can stop there or continue to calculate the remainder as a decimal.
Align a decimal point in the answer with the decimal point in the dividend and drop down a zero to create the next number. In the example, place a decimal point after "28" and drop down a zero to create the new number 40.
Repeat the procedure on the new number or numbers until you have a zero remainder or the remainder repeats. In the example, you'll keep getting 4 as a remainder, so the quotient is 28.3 with the 3 repeating forever. To illustrate that, just write the first "3" and place a bar over it to signify it as a repeating value.
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