Could somebodytell me the rules on how to divide, multiply, add, and subtract decimals?

Question

i was never told by anybodythat there WERE rules. and now im being tested over them tommorrow and i really need help.

please help.

Answer 1

3.1 2.9 7.8 sorry, you must find
+2.1 +2.1 -3.4 where I carried ones,
------- ------- ------- etc. can't make little
5.2 5.0 4.4 ones.

addition, and subtraction, decimal stays in the same place (comes straight down) and so does your digits.

2.6
x 3.1
-------
2 6
7 8 0
--------
8. 0 6

now if you check this problem on the calculator, you will get 8.06. What I was told in middle school somewhere, was that you solve the problem as if there was no decimal point at all. Then, you put the decimal point over, from the right side of your answer, for how many places over it is for the
top, and bottom numbers your multiplying.

2 .6 (6 is one place over)
2 .1 (1 is one place over)

806 go two places from the right of that 6

8.06

if you had to multiply 5.67 and 3.2 (you should get 18.144, do it) you can see right now, with that .67 and .2 your answer will go three places over, from the outside of that last number of your answer.

9.5 divided by 2.5 = 3.8

there's a cheatin way to do this. move that decimal point for divisor and dividend one place to the right. you'll end up with 95 and 25.

95 divided by 25 happens to give you the same answer- 3.8

thing about dividing decimals, most of your answers won't be pretty like that.

if you have 25.4 and 1.25 you move it one space down, you'll get 254 and 12.5. But both's decimals have to be to the end. So,
make that 12.5 become 125, and for 254 add a 0 to the end. (I don't know why, but that's the number you must add to fill up the space.)

you'll get 2,540 and 125. Now do a problem 25.4 divided by 1.25, and 2,540 divided by 125, and see what happens.

and if your division stuff has ANYTHING to do with fractions, say so, 'cause that's another bag of trauma biscuits

Answer 2

follow the same rules for whole numbers but follow these rules
while adding or subtracting mke sure that the decimal point of both the fractions are in the same vertical line
0.0088675+198.08
0.0088675 +
198.08
----------------
198.0888675
while multiplying operate without the decimal and shift the decimal as many places to the left after the multiplication
e.g. 5.25*0.0975 first multiply 525 and 975=511875 now the no of places of decimal to be shifted=2+4=6 so the answer is
0.511875
or suitably multiply and divide the no(s) by multiples of 10 to get rid of the decimals and do the correction in the end

Answer 3

make sure the decimals always line up. when you multiple, carry down the decimal and make sure the spacing is the same like...if the question is 3.84X4.86...then the answer should be 18.66...meaning that since the decimal point is in tenths place (or two places over) that's where the answer should be. With addition and subtraction, just line the numbers up with the decimals and carry down the decimal. Division rules are the same as multiplying except that if you have a whole number and a decimal, you have to put the decimal in the whole number..for example.....3/4.5...when you set it up it should look like 3.0/4.5.

Hope it helps..I haven't done decimals in years.

Answer 4

for addition and subtraction line them up ie. keep them in the same position tenths, hundreths ect. when you mulitply you count the number of places after the decimal and them add them example 10.222 X 10.333 has six total numbers after the decimals so the answer has six numbers after the decimal 105.623926, to divide the decimal stays in the same place you do not shift it

Answer 5

Google "Rules for working with decimals" then click on the first one.

Answer 6

First of all, if you have parentheses, you do those first. Then you start from the left to the right.

Answer 7

dont feal like it lol