1. Turn 4 into a fraction --> 4/1
2. Divide 4/1 by 1/10 by switching 1/10 upside down and multiplying 4/1 by it:
4/1 x 10/1 --> Carry out the multiplication. Multiply the numerators together and the denominators together.
4/1 x 10/1 = 40/1
Convert 40/1 into decimal form =
40
