Expert: Wei Chong - 6/18/2008

Question
The question is:
Find the density of a material that has a mass of 2kg and a volume of 5m3. Express your answer in both fractioan and decimal form.

Answer
Hi Amanda,

Before we begin, we need to understand how fractions are related to decimal numbers.

The following link contain a math video that will explain basics behind fractions (scroll the page down to watch video):

http://www.mathexpression.com/understanding-fractions.html

Now, let's solve your question step-by-step.

The formula for density is given as follows:

Density =  mass/volume

Hence, since the mass is 2kg and the volume is 5m^3, we just need to substitute these values into the formula:

Density = mass/volume
       = 2 kg/5 m^3
       = 2/5 kg/m^3    


Now, we can see that 2/5 is the density expressed in fraction form.

How about decimal form? After going through the basics behind fractions, we should know that:

  2/5 is equals to 2 divides 5

This means:

2/5 = 2 ÷ 5
   = 0.4 kg/m^3 <-- 0.4 is the decimal form


That's all.

Best Regards,
Wei Chong