Idiot\'s Guides Basic Math and Pre-Algebra

78 Part 1: The World of Numbers

WORLDLY WISDOM

If you’ve done your division and still have a remainder, you can add zeros to the

dividend and keep dividing. If your dividend was a whole number and you still have

a remainder when you’ve divided through to the ones place, add a decimal point and

some zeros. Then keep dividing to get a decimal in the quotient.

Step-by-step, the process for long division of decimals looks like this:

• Make an estimate of the quotient.


• Move the decimal point to the end of the divisor.


• Move the decimal point an equal number of places in the dividend.


• Divide normally and let the decimal rise directly up into the quotient.

CHECK POINT

Complete each multiplication or division problem.

21. 4.92 v 1.5


22. 68.413 v 0.15


23. 95.94 z 7. 8
    24. 461.44 z 1.12
    25. 5,066.518 z 8.6

Converting Fractions

To convert a common fraction to a decimal fraction, do what the fraction tells you. No, they don’t

actually talk, but every fraction is a division problem. The fraction 43 is the number you get when

3 is divided by 4. To change it to a decimal, do the division.

WORLDLY WISDOM

You can use the word TIBO to remind you that when you convert a fraction to a

decimal, you put the top number, or numerator, inside the division sign, and the

bottom number, or denominator, outside and then divide. Top In, Bottom Out, or

TIBO.

To c h a n g e

5

8 to a decimal, do the division problem^85.

Add a decimal point after the 5 and add some zeros. Do the division, letting the decimal point

from the dividend f loat straight up to the quotient.