Documentation
Teacher’s Name: Sophia Arianna Chokr
Date: February 20, 2019
Cycle: Upper Elementary
Grade: 6
Theme: Finding Midpoint
Unit: Geometry
Subject: Mathematics
Student Learning Outcomes
After this lesson, students will be able to:
o
Define midpoint
o
Deduce the formula for finding midpoint
o
Apply the midpoint formula
Student Background
Students know what distance is and how to measure it. They also know how to use a
compass to find angle bisector. (Most of the unit is focused on angles which that have
learnt but the concepts are not very applicable to this lesson).
Rationale
o
Midpoint is an important concept for future geometry
o
Understanding and finding midpoint is also very important for architecture and
many other real-life problems
o
Differentiate between midpoint and equidistant
Materials Needed
o
Pencil and chopstick
o
Tape
o
Blank papers
o
Rules (students should bring their own, but bring extra incase)
o
Compasses (students should bring their own, but bring extra incase)
o
Laser pointer (1 for teacher)
o
Measuring tape (1 for teacher)
Instructional Procedure:
Before Phase (5 mins):
o
Place a pencil on edge of the table (so half of the pencil is not on the table),
tape the pencil so it doesn’t move. Ask one student to try to balance the
chopstick on the pencil. Discuss with students’ what requirements are needed
for the chopstick to balance (the chopstick must sit right on the middle). If
confused ask students to predict if the chopstick will balance if you lay it a
certain way (obviously not in the middle).
During Phase (45 mins):
o
Pass out the blank papers to all students, instruct the students to draw a
segment that stretches from one side of the paper to the other. Ask students
how they could find the middle of the line. If applicable to their methodology,
ask students to create a formula. Discuss the different methods (and formulas)
the students used to find the middle of the line (expect some students to have
folded the paper in half and others to have measured across and divide by 2).
o
Ask students to pull out compasses, hand out one blank paper to each group.
Ask the students again to draw a segment on the paper. Ask students to try out
how they could find the middle of the line using their compasses. Instruct them
to check their work by measuring. For struggling groups ask them what an
angle bisector is (a line in the middle of the angle) to guide them. For early
finishing group, spread the students across the room to aid the other groups.
Discuss the methods used (and test to ensure they work). Ask students to guess
the definition of midpoint (expect students to say middle).
o
Close blinds and turn off lights. Have one student stand on the opposite side of
the class as you point the laser to that student. Ask a student to measure the
length from the teacher to the student, then ask them what the middle is (divide
the distance by 2). Measure this distance but in a different direction (not at the
midpoint). Place a student at that point. Ask students if they think that student
is at the midpoint of the distance from the teacher and student 1. Discuss. Ask
a student to show where the midpoint is (the laser should now touch this new
student to show midpoint is on the same path). Recap definition.
Assessment Procedures
Give each group a paper to draw a segment. Then have the groups pass the segment they drew
to the group next to them. Instruct students to find the midpoint by measuring, switch papers
again, now ask students to find the midpoint using the compass. Observe each group working
and ask each group to explain the procedure.
Reflection