How to do Simple Calculations in Your Head - Addition

Let's face it. Math is not everyone's favorite subject.more than one way to skin a cat". Why you would
Most people would rather use a calculater to figurewant to skin a cat or even have more than way to
out how much something costs with tax or theydo it is beyond me but I digress. What that phrase
depend on the cashier and the cash register tomeans is that there's more than one way to solve a
determine how much chage they should get back. I'mproblem and math is no different. However for my
not one of those people.examples I'm going to show what in my opinion is
For as long as I can remember I have always beenthe easiest method.
playing with numbers in my head. Now I don't have aLet's do another one but this time with three digits:
doctorate in math or nuclear engineering or anything267 + 148
like that. I'm just your average guy who happens toNow don't panic! For this one we'll use my divide and
like math and playing with numbers in his head. If I'mconquer method. This means that we'll break one of
watching something on TV or listening to the radiothe numbers down into multiples of 10 so we'll have
and someone mentions a date that something wassome zeros on the end and this will make adding a
created, I immediately do the calculation in my headwhole lot easier. Let's pick the second number, 148.
to figure out how many years that is. I'm probablySo now we have:
not the only person who's like that but I'm guessing267 + 100 + 40 + 8
that there aren't many of us.See how easier it becomes now? Adding 267 and
Let's begin with a small example:100 is easy.
93 + 48267 + 100 = 367
Believe it or not this is really simple. The trick is toTo add 367 and 40, change 367 to a multiple of 10
round one or both of the numbers up(or down) to aby subtracting 7 and making it 360. Remember it's a
multiple of 10. This is because it's easier to addlot easier to add numbers that end with a zero.
numbers that have a zero on the end. So going backSo now we have:
to our example here the easiest solution is to add 7360 + 40 + 8 = 408
to 93 to make it 100.Now going back to "My Little Rule" at the top, we
Our problem now becomes:subtracted 7 at the beginning so we must add it
100 + 48 = 148back.
Now this is not the final answer. I have what I like to408 + 7 = 415
call "My Little Rule". Basically it states that whateverThis might look like a lot of steps to do but when
you do at the beginnig, you must do the opposite atyou practice doing it in your mind it's really fast after
the end and with the same amount. In this caseyou get the hang of it. There are a lot more
what we did at the beginning was add 7 in order toexamples I can do here but that would make for an
make the addition easier. We must thereforearticle the size of a book so I think I'll stop here for
subtract that same amount from the result above tonow. Hopefully you get the basic idea. I'll be writing
get the answer.more articles about doing math problems in your head
148 - 7 = 141so watch for them. You can also find more on my
Now you've probably heard of the phrase "There'sweb site. See you next time.