Multiplication by 9s trick

Hold out your ten fingers in front of you.
Whatever # you are multiplying by 9, count your fingers from left to right til you get to that number. Hold that finger down. The answer is the number of fingers before the held down finger and the number of fingers held up after that finger. Those are the two digits.
Ex. 9×3
Hold down the third finger. There are two fingers before the held down finger and 7 after it. The answer is 27.
WOW. Sure would have been useful about 23 years ago, lol.