Geology Rocks Equations

Mr. Anderson is a geologist (earth scientist) and has a laboratory full of rocks. He knows that each rock weights exactly one pound (+1) and he would like to figure out how many rocks are in each crate. Each crate contains the same number of rocks. To figure out without opening the crates, Mr. Anderson places crates and rocks on a scale until they are balanced. Using his math skills, he is able to reason how many rocks are in each crate without having to look inside.

Research question: How many rocks are in each crate ? (Each problem number has a set of crates with different amounts of rocks)

1. How many rocks are in each crate? ______

More on the BACK 5. How many rocks are in each crate? ______

A. How did you determine how many rocks were in each crate? First, we… ______then we ______B. Equations are used to represent real life situations. The equations for #1 and #3 are already written below. If x is a crate (unknown amount of rocks) and the constant is the number of loose rocks, write the equations for the rest of the pictures above. 1. 2x = 6 2. ______3. 3x + 4 = 10 4. ______5. ______6. ______7. ______C. What does the x represent? ______What represents the loose rocks? ______D. What are you trying to figure out? What are you trying to solve for? ______E. Mr. Anderson wrote down the following equations, but did not draw any pictures. Can you find the value of x in each? (HINT: think of each x as a crate of rocks) 8. 2x + 5 = 7 9. 6x + 1 = 12 10. 3 + 6x = 15 11. 3x + 4 = 19 12. 4x + 5 = 17 13. 30 = 6 + 4x How do you solve an equation when it has multiplication and addition with x? ______