Fractions, Decimals and Percents Mini-course

Session Seven

Developing Percent Concepts

HW Review & Online Game

Share your solutions to Decimal Problems II by discussing the following questions:•What was the longest / shortest path you found?•What logic or method did you use to make sure you always moved to a larger value?

Objectives

• To use grids, number lines and color tiles as models for illustrating percent concepts.

• To build on participants existing number sense with percent.

• To review and extend participants understanding of NCTM Number and Operation Standard.

Percent ConceptsDefine each word:•Centipede •Centimeter •Century •Cent•What do these words have in common?•“cent” in percent relates to these words and to 100.

What does “per” mean?

For example: -- Miles per hour -- Cost per person -- Participants per teacher Percent: for every one hundred

Let’s think of percent as making comparisons to 100!

Percent Concepts

Percent Examples

Estimating Percents• BLM 40

• Each Square is worth 100 percent

• Estimate the percent for the shaded portion and write it below each square.

Checking Estimates

• Use the transparency overlay to find the exact percent shaded by counting the squares.

• The grid fits perfectly over the squares.

• Discuss how far or how close you were in your estimates with your partners.

Finding Percents of Different Numbers

• BLM 41• Illustrate the

percentages with color tiles

• Form a collection that fits each description.

• You do not need 100 items to illustrate the percent.

Percent Grids

• BLM 42

• Work with a partner to figure out which portion to shade to represent the %.

Percent Number Lines

• BLM 43

• Next estimate the % represented by the dots on the number line.

NCTM Numbers and Operation Standard

Students can develop a deep understanding of rational numbers through experiences with a variety of models such as fraction strips, number lines, 10 x 10 grids, area models, and objects.

Percents 0 - 100• Write your initials on each dot and place

them on the five foot number line.

• Place your green dot to show your confidence with fractions, decimals and percents prior to taking the class.

• Place the yellow dot to show your confidence after taking the class

• What do you think has contributed to the growth?

Reflection and ClosureHomework: •Bringing Mathematics Home 7•Top Ten Tips for Parents•Percent Problems•Please bring your fractions strips from Session 6 to class for Session 8.