Faster Addition

It's really hard to add 56,54,35 and 38 really fast in your head.My computer math teacher taught me this trick.Take each second digit in each number and add a zero in it's place .So now it's 50,50,30 and 30.That equals 160,but remember you still have those second digits which are 6,4,5 and 8 which adds to 23 ,add the 23 to the 160 which adds to 182.If you have a problem like 16 plus 20 take away the 6 which makes it 10,now add the 20 plus the 10 which makes it 30 now take that 6 you took away from ten and add it to the 30 which makes the final answer 36.