Mass is the amount of matter in an object. The mass of an object can be measured with a balance scale. The unit for mass is grams. The abbreviation for grams is g. When the pans contain exactly the same mass, the beam is in balance. A paperclip has a mass of 1 gram. Observations help you make predictions. 1. Click on the to watch the video. 2. Use your iPad to take a video of you predicting the mass of your rock. 3. Click to open the template. 4. Upload your prediction video. 5. Measure the mass of the rock. Take a . The photo should show the entire balance scale. 6. Upload your photo. 7. Use the tool to write the mass of the rock. Include the unit (g). 8. Record a summary of the activity. Be sure to use the words mass, grams, and balance scale. 9. Click the green to save.