It is a question with infinitely many answers.
For example,
21 * 0.1
210 * 0.01
7 * 0.3
3*7 = 21
3 times blank equals 18,000 = 54000
Blank = zero.
7 times blank = 2 times blank
It is: 9 times 7 = 63
blank = 9
22.1133444 approx
The answer is three. 6 x 3 = 18
It could be: 9*5 = 45
10
11
100 times 130 equals 13,000