Answer:
4 x 1/10 = 4/10
Explanation
One way to think about it is you turn 4 to a fraction which would be 4/1. then you multiply the numerators(the top numbers) and the denominators(bottom numbers) and that's that. so 4 x 1 = 4. and 1 x 10 = 10. then put 4 over 10.