NGSS
HS-ESS1-6
3 lessons teach this standard. Every lesson is interactive, and every one prints as a worksheet with a separate answer key.
Earth and Space Science · Chapter 4 · Lesson 2
The clock is the ratio, not what is left.
Earth and Space Science · Chapter 4 · Lesson 3
Almost all of it happened before anything had a skeleton.
Earth and Space Science · Chapter 4 · Lesson 4
The largest one was not the one with the asteroid.