Sometimes when numbers don't end with 0 or 5 they can be a little trickier to figure out in your head.
I enjoy doing things as fast as possible, and if at all possible without the use of a calculator. One way I can figure out a quick math problem, for example how much money I have left to spend at the grocery store or something similar is to use the compensation method.
This method is my favorite because it works well for me and it works fast. I am able to do the math and solve problems pretty quickly using this process. Here is an example: Lets say we have to figure out what 73-59 is. The first thing I do is look at the numbers to see if the end digit is the same, or near the same; in this case it is not. (I will show an example of that next) So I see that 59 is close to 60 and round up, then in my head I subtract 60 from 73 which gives me 13. I then have to remember to add that one back into the equation giving me the final correct answer of 14.
Lets try another example: 48 - 39= ? This time since the ending digit is near the same I just adjust the 48 to 49. Then I calculate 49-39, which is 10. I again have to remember to adjust the total by 1, since this time I added 1 to the first number I now must subtract 1 from my estimated total. I have a final answer of 9!
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