f65
Factoring Large Numbers- An AskERIC Lesson Plan
Lesson Plan #:AELP-ATH0005

##
Factoring Large Numbers

An AskERIC Lesson Plan

**AUTHOR:** Tim Olson, Meadow Valley Middle School Panaca, Nevada

**GRADE LEVEL/SUBJECT:** Grade 7, Math

**OVERVIEW:**

Know the basic rules for divisibility ie: 2's are even, 3's add the digits
etc.

**ACTIVITIES:**

Have students choose a large even number, say 642, how could you tell what
numbers that are all prime would go into this number?

Let the students discover how many times they can divide out a group of small
numbers. Then introduce the tree of organization to the process.

642
321*2 2 is prime, circle it.
17*3 both are prime, we can stop.
This process can be used for many different things in basic
math skills including, fractions, common denominators, and
decimals but division skills can only be improved by doing
411
basic practice.
ADDITIONAL ACTIVITIES: Factor method for large fraction
reduction.
884
---
1224 884 1224
221* 4 102* 12
17*13 2*2 51*2 3*4
2*2*13*17
2*2*2*3*3*17
leaving 13\2*3*3=13\18

May 1994
These lesson plans are the result of the work of the teachers who have attended
the Columbia Education Center's Summer Workshop. CEC is a consortium of teacher
from 14 western states dedicated to improving the quality of education in
the rural, western, United States, and particularly the quality of math and
science Education. CEC uses Big Sky Telegraph as the hub of their
telecommunications network that allows the participating teachers to stay
in contact with their trainers and peers that they have met at the Workshops.

0