Math Portal Home > Middle School Lesson Plans > Get a Half-
life!: Teacher Notes  Get a Half-life!: Teacher Notes
Conceptual Understanding  Data Collection Graphing Calculator
Line of Best Fit Interpret Data  Procedural Knowledge
Calculator Commands Exponential Decay Organize Data Graph Data
Curve of Best Fit  Problem Solving  A decay function is one in
which the values decrease by a constant factor, but it is not
linear! These functions are often used to model the decay of a
radioactive element. The half-life of a substance is the time it
takes to reduce its initial effectiveness by one-half.  Students
work in pairs.  Each pair needs:    • 1 cup of m&m's   • 1 paper
plate or box   • 1 graphing calculator    1. Collect the Data
1. Pour m&m's out and count your beginning sample size (N). This
will be your N value when T = 0. Enter this value in the table
below and put the m&m's back in the cup.     2. Shake the cup
gently and pour the m&m's out in the box or on the paper plate.
3. Remove all the m&m'