**Ratio, Percent & Proportions**

Rosalyn Winston Walt Disney Magnet School

4140 N. Marine Drive

Chicago IL 60613

(773) 534-5846

**Objectives**:

To write fractions as percents for seventh graders.

To find the percent of a number.

To find percents using proportions.

To calculate the weight of objects (beads) in grams given specific percents.

To verify the weight of objects (beads) on a scale in grams in cooperative

learning groups.

**Materials Needed**:

calculators

electronic scale measures in grams and ounces

clear plastic liter bottle

clear containers for each cooperative learning group

multi-colored chalk or overhead transparency markers

containers to hold objects

beads of various colors

**Strategy:**
"The phenomenological approach to mathematical instruction asks a question
which requires the use of mathematics to answer it. The question must be based
on a physical entity present for observation and use the mathematical processes
you are teaching at the time. The answer to the question must be verifiable by
direct observation."
How much will the beads that each person has weigh? Four cooperative group
members are sitting around a pile of beads weighing 237 ounces. The first
person takes 4 beads from the pile, the second person takes 3 beads, the third
person takes 2 beads; the fourth person takes 1 bead from the pile. They
continue the process until all the beads are gone. Each person now holds a
percent (10%, 20%, 30% or 40%) of the original pile.
Each cooperative math group will do their calculations first.
The total weight of all the beads is 237 grams. The first student should have
130 grams. 40% of 237 is 130.00 grams. The second person should have 30% of
237 grams or 71.10 grams. The third person should have 30% of 237 grams or 47.4
grams. The fourth person should have 23.7 grams or 10% of 237 grams.
Check each individual's calculations.
Verify each individual's beads weight on the electronic scale.
**Performance Assessment**:

Give the cooperative math groups different bags of beads to calculate weight

with the same percentages 40%, 30%, 20%,10% or, give them new percentages to

investigate.

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