1 1/2 can be written as an improper fraction. To do this you multiply 1 by the denominator which is 2 and add it to the numerator which is 1 and then put the resulting number over the denominator.
1 times 2 is 2.
2+1 is 3.
We now put 3 over 2.

3 divided by 2 multiplied by 2 would cancel out the 2's so the resulting answer would be
3.
Or you can multiply them.
