|
Aliquot Parts |
Mental math using Aliquot parts is very simple and effective. All you have to do is look at one of the factors as a fraction made of easier numbers to deal with for example:
| quickly, multiply 328x25:
Normally this problem makes people think, "ok 25x300+25x20+25x8 or even 25x330-50 or something like that, all of which is too many steps and unnecessary all you have to do is remember a simple fraction 25=100/4 thus the problem becomes 32800/4 treat the 32 part as if it were just a 32 instead of 32000 and the 800 part is easy so the answer is: 8200 simple huh? try another:
|
How about 2048x50?
well, to do that all we have to do is look at 50 as it's fraction equivalent 100/2 so whatever number we're multiplying by all we do is add 2 zeros to it and then divide each digit by 2.
for example:
|
2048x50= 2048x100/2 204800/2=102400 |
try some more:
|
5050x50 |
842810x50 |
|
16888444x50 |
2020202020x50 |
always remember to treat the digits of the number as single numbers so in the last example the answer should be 101010101000 because half of 20 is 10.
Like I said multiplication with Aliquot parts is as easy as eating pancakes. This has interesting meaning for multiplying by 5's for example if you look at 5 as 10/2 then all you have to do is half the number you are multiplying and add a zero (or in the case of an odd number just move the decimal over on place.
for example:
|
222444666x5 =1112223330 |
or
|
444466681x5 =222233345 |
Like I said easy as eating pancakes.
Can you think of how to make other numbers into Aliquot Parts?
here's a few
|
4441680x250?=4441680x1000/4 |
24268x500=24268x1000/2 |
|
644080x12.5=644080x100/8 |
44444x75=44444x(3x100)/4 |
more to come :-)
