Hey there!
1. To solve 9 x 5 , I could add the number 9 five times . . .
9 + 9 + 9 + 9 + 9 = 45
9 x 5 = 45 <----
2. I would use the same strategy as the first one, except add the number 8 five times . . .
8 + 8 + 8 + 8 + 8 = 40
8 x 5 = 40 <----
Hope this helps you.
Have a great day!