MENTAL MATH TRICK 1: TENS AND ONES
The first trick is simple. If I say “What is 346 plus 211?” You can make your life
easier by breaking down the 211 into 200 + 10 + 1, and then adding each
separate piece. So 346 + 200 = 546, then 546 + 10 = 556, and finally 556 + 1 =
- This trick breaks a complicated addition problem into a sequence of
problems that are so easy they are almost automatic. They save you time and
energy, and you are less likely to make a calculation mistake. The same goes for
multiplication. “What is 56 times 14?” First, do 56 × 10 = 560, then do 56 × 4 =
224, then add them together to get the answer: 784. Perhaps that middle step (56
× 4) was too complicated to do in your head? Just break it down: 50 × 4 = 200,
and 6 × 4 = 24. Add them together to get 224.
This might feel funky at first, but with a bit of practice, “Tens and Ones” can
save you oodles of time and energy.
MENTAL MATH TRICK 2: KNOW YOUR PREMDAS
The easiest and most common mistake to make in mental math is to mess up
your order of operations. It’s possible you haven’t reviewed your PEMDAS in
years. Refresher—go in this order: Parentheses, Exponents, Multiplication and
Division, Addition and Subtraction. Remember that when you’re doing addition