You can multiply by 9 on your fingers.
Hold hands out, fingers splayed, thumbs towards each other. 🙌
9*2 put your left ring finger down (the 2nd finger). Left of that is tens place, right of that is the ones place.
So 1 on the left, 8 on the right of the downed finger.
9*5 put the left thumb down (5th finger.) 4, 5. 45.
The trick that I teach the shorter humanoids is to subtract 1 from the multiplier of 9, put that number in the 10s column, then complete the nine and put that in the 1s column.
Then we spent some time finding the pairs of numbers that make 9. 1+8. 2+7, 3+…7+2, 8+1. I have to be explicit in this part, or they will shortcut to 3, (use fingers to count to 9) uh 6? They usually learn it in a day or two. To get them to flash to instantly know their times tables takes longer.
