How to work out density

Part ofShape, space and measures

To play this video you need to enable JavaScript in your browser.

This video can not be played

A short video showing how to work out density.

Skip image gallery

Image caption,
Click to see a step-by-step slideshow.
Image caption,
WHAT YOU NEED: a ruler, whiteboard, calculator, red pen and green pen.
Image caption,
STEP 1: Find the volume and mass of the object. Here it is 2 cm³ and 38 g.
Image caption,
STEP 2: Write out the problem, circle the key pieces of information and draw a bar. Label the whole bar 38 g. Draw a second bar directly underneath the first and label the end 2 cm³.
Image caption,
STEP 3: Write out the equation to work out density. Use the ruler to draw a vertical line in the middle of the bottom bar. Shade the area to the left, label this 1 cm³. Repeat on the top bar, labelling the shaded area with a question mark.
Image caption,
STEP 4: Write out the equation. Here it is the mass, 38 g, divided by the volume, 2 cm³. Before you use a calculator, can you estimate in your head what the answer might be?
Image caption,
Use a calculator to check your answer. You've done it! The answer is 19 g / cm³. This is the equivalent of the shaded area of the top bar. Did you know the density of pure gold is 19 g / cm³? Lead is only 11 g / cm³.

Where next?

Want to dive deeper? Explore more with Bitesize.

Shape, space and measures

More on Shape, space and measures

Find out more by working through a topic

Pythagoras' theorem
count
27 of 50
WATCH: How to prove Pythagoras' theorem
count
28 of 50
Angles and triangles
count
29 of 50
WATCH: What are angles?
count
30 of 50