I figured out how to multiply any 3 digit number times 11 and get an instant answer

Full disclosure: I’ve been taking mushrooms

Let’s say it’s 178 * 11

Answer:
1. Right digit of top number always same = 8
2. Next digit is always the right digit of the right two numbers added together = 7+8 = 15 = 5.
3. If the answer to 2 above is 10 or greater carry the one to the addition of the left two digits = 1+7 (+ carried 1 from the 15 answer in point 2 above) = 9
4. Since the answer from point 3 is less than 10 you don’t have to carry one for final digit so it’s just the left digit of the original top number = 1

Answer: 1,958

Two digits is easier and well known

78 * 11
1. Left number (plus carry if from adding 7+8) = 7 + 1
2. Middle number right number from 7+8 = 15 = 5
3. Right number = 8
Answer: 858

For two digit numbers under 55 like 10-54

54 * 11
1. Left number + sum of digits + right number
2. 5 + (5+4) + 4
Answer: 594