A rectangular prism has a length of 1 1/4 centimeters, a width of 4 centimeters, and a height of 3 1/4 centimeters. What is the volume of the prism? Enter your answer in the box as a simplified mixed number or a decimal.

To find the volume of a rectangular prism, you just multiply the length x width x height.
So
1 1/4 x 4 x 3 1/4 = volume (and since they are all centimeters you don't have to worry about converting units)
You can also use decimals instead. So either the above equation or 1.25 x 4 x 3.25 = volume
and if you don't know the decimal for a fraction just pop it into a calculator if you have one, so to find 1/4 as a decimal just do 1 divided by 4 in the calculator. There are ways you can do it without a calculator but it's easier if you have one. 

So the volume of this cube would be 
16.25
or
16 1/4