Number and Operations in Base-10

Problem 555:Exploring Your Weight Across the Solar System
Students estimate their weight on different planets, moons and asteroids. [Grade: 6-8 | Topics: proportions] (PDF)

Problem 545:Measuring Atmospheric Trace Gases Using Parts Per Million
Students convert from percentage units to parts per million and compare trace gases in the atmospheres of various planets. [Grade: 6-8 | Topics: percentages; unit conversions ] (PDF)

Problem 400: The Most Distant Objects in the Universe Students use a table of the most distant known events and objects in the universe to create a timeline of the universe soon after the Big Bang. [Grade: 6-8 | Topics: Working with millions and billions; elapsed time] (PDF)

Problem 356: Calculating Molecular Mass
Students count hydrogen, carbon and oxygen atoms in a molecule of adefovir dipivoxil and calculate its mass and formula.[Grade: 6-8 | Topics: Counting; Scientific Notation] (PDF)

Problem 231: Star Magnitudes and Decimals- Students work with the stellar magnitude scale to determine the brightness differences between stars. [Grade: 5-8 | Topics: Multiplying decimals.]