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Cool math tricks!
Here are some neat math short-cuts that you can do in your head
142
213
+431
When you see a math problem like this, you were probably taught to add the right-most column first. Then the middle, then the left-most. But, doing it from left to right is actually much faster!
Start with the left column. 1+2+4 is 7. Keep 700 in your mind. Then add the middle column. 740 -> 750 -> 780. Then the last column. 782 -> 785 -> 786
See how much faster and quicker that was? 
Here's another one:
346
473
+170
So, first add the left column. 8(00). Then the middle column. 180. Uh-oh, its more than 100. So add 100 to 800, and you're left with just 80. Now the last column: 989 is the final answer!
Here's one with multiplication:
24
x12
Now, do the right column. 2x4=8. Now, cross multiply 4x1, and 2x2, and add the sum together. which is 8. Now multiply The left column, 2x1. Which is 2. The answer is 288. Pretty cool huh? 
Here are some more problems to practice with. Check them with a calculator to see if you're right.
63
x52
532
125
+842
32
x64
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