Sunday 27 January 2013

Adding Decimals:

ex. 0.2 + 0.4 = 0.6

add 2 plus 4 to get 6 then add 0 plus 0 to get 0. then your answer is 0.6.


Subracting Decimals:

ex. 0.3 - 0.2 = 0.1

subtract 3 by 2 to get the number 1 then subract 0 minus 0 to get 0. Then your answer is 0.1.


Multiplying Decimals:

ex. 16.1 x 2.4 = 38.64           16.1
                                            x  2.4   
                                               644   
                                           +3220
                                            38.64

Multiply 4 by 1 to get 4 then multiply 6 by 4 to get 24, carry the 2. multiply 4 by 1 plus 2 to get 6 which equals to 644
start a new row, put 0 at the ones place. then multiply 2 by 1 to get 2 then multiply 2 by 6 to get 12 carry the 1 to get 3 which equals to 3220. now add 644 with 3220 to get the answer of 38.64.


Dividing Decimals:
                                                             6.23 
ex. 31.773 divided by 5.1 =       51  317.73
                                                        -306     
                                                         0117
                                                        -  102   
                                                             153
                                                        -   153  
                                                            000
 Remember :
Move the decimal to the right.

To get the answer you need to know how many 51 is in 317 which is 6. then multiply 6 by 1 from 51 then multiply 6 by 5 to get 30 now put them together to get 306. then subract 317 by 306 to get 11 then lower the 7 from 317.73. now calculate how many 51 is in 117 which is 2. now multiply 2 by 1 to get 2 then multiply 2 by 5 to get 10. now put 10 and 2 together which is 102. then subtract 117 by 102 to get 15 then lower the 3 to get the total of 153. then calculate how many 51 is in 153 which is 3. now multiply 3 by 1 to get 3 then multiply 3 by 5 to get 15. now put 15 and 3 together to get 153. then subrtact 153 by 153 which is 0 and that is where you stop and get your answer.
                                         



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