Tuesday, September 23, 2013 is the Autumnal Equinox. It is the time of year when the imaginary plane that might pass through the Earth’s Equator would also travel through the center of the Sun. At this auspicious moment the number of sunlight hours and night time hours are about the same all over the Earth and in the Northern Hemisphere we move into the Fall season.

# Doubling your money

My friend and I were arguing about how long it would take me to double my investment amounts. How will your students figure this out? Are there any tricks? Explore investing and exponential growth as your students discover “The Rule of 72.” Also check out this Rule of 72 calculator (or our calculator below) & this video from Khan Academy on the Rule of 72.

# Fantasy Football

In the midst of another NFL season, we introduce students to Fantasy Football. Students first calculate football points given touchdowns, yardage gains and interceptions. They are then challenged to generalize an equation for that gives a player’s total fantasy points. Students solve equations as they try to find the number of passes, touchdowns, or interceptions that yield given point totals. Students can also compete in their own fantasy football competition within the class. This lesson is ideal for teachers that want to work on equations with their students or for a group of football fans.

# Saffron and paella

In order to cook Paella (a delicious Spanish rice dish) I needed to buy Saffron spice. It was hugely expensive. So, I’ve decided to start a business of growing saffron and becoming immensely wealthy.

# Labor Day

In this short activity, students learn the meaning and history of Labor Day as they look for patterns emerging from the Labor Day dates over more than past years. Students then use those observed patterns to predict future dates of the holiday.

**The activity:** LaborDay

# Drill Bit Fractions

** Act One:** Drill bits are measured by the diameter of the bit in inches. The drill bits below are ordered left to right in increasing size.

The numerators in the fractions have been blacked out. What *could *the numerators be? Explain your reasoning.