# Solutions

**KM#1: StreamFlow for the Animas River (Level 1)**

**Mathematical Content:** Area, Volume, Unit Conversion

**KM#2: Sunset Crater (Level 2)**

**Mathematical Content: **Basic algebra; solving equations

**KM#3: Snow Melt and Stream Flow for the Animas River(Level 2)**

**Mathematical Content:** Area, Volume, Unit Conversion, linear equations.

**KM#4: The Size of the Earth (Level 2)**

**Mathematical Content:** Geometry (radius and circumference of a circle; volume of a sphere); interior angles.

**KM #5: The Size of the Earth—Estimation in Arizona (Level 2)**

**Mathematical Content:** Geometry (radius and circumference of a circle; volume of a sphere); interior angles.

**KM#6: Location of the Epicenter of an Earthquake (Level 2)**

**Mathematical Content:** Basic algebra; equation of a line; radius of a circle

**KM#7: Impact Processes - Meteor Crater (Level 2)**

**Mathematical Content: **Basic algebra, solving simple equations

**KM#8: Age of the Earth (Level 2+)**

**Mathematical Content:** Basic algebra; exponential equations; logarithms.

**KM#9: Mass and Density of the Earth (Level 3)**

**Mathematical Content:** Geometry (radius and circumference of a circle; volume of a sphere); interior angles; Newton's Law of gravitational attraction; formulas for density and force; solving equations involving kinetic energy, mass and volume

**KM#10: Layers of the Earth (Level 3)**

**Mathematical Content:** Basic algebra (distance, rate and time); geometry; Snell’s law

**KM#11: Size, Mass and Density of the Earth (Level 3)**

**Mathematical Content:** Geometry (radius and circumference of a circle; volume of a sphere); interior angles; Newton's Law of gravitational attraction; formulas for density and force; solving equations

**KM#12: Age of the Earth (Level 4)**

**Mathematical Content:** Basic algebra; exponential equations; logarithms; linear regression.

**KM#13: Impact Processes: Meteor Crater (Level 4)**

**Mathematical Content: **Algebra, power and linear equations, linear regression, solving equations involving kinetic energy, mass and volume.