**Real Numbers in the Real World**

Ulysses Harrison Dunbar Vocational High School

3100 South King Drive

Chicago IL 60616

312-534-9000

**Objectives**:

Students will be able to group the set, R, of real numbers into two different

sets: R **>** 0, R < 0.

Students will be able to use parentheses to change the order in which

exponentiation, multiplication, division, addition and subtraction are performed

by using the TI-34 calculator.

Students will be able to work problems throughout the set of real numbers using

the TI-34 calculator without preference for positive numbers.

**Materials Needed**:

Set of TI-34 Calculators--one for each student.

**Strategy**:

Inform the students that the real number system consists of natural numbers,

whole numbers, integers, rational numbers, and irrational numbers. Students

must be able to comfortably use the whole set of real numbers to perform the

mathematics operations in order to be successful at working problems in the real

world. Give example problems that include numbers in the subsets of the real

number system initially. Have students work these problems on the calculator.

Finally, include problems that involve all the real numbers and all the

operations. Have students work these problems on the calculator. Emphasize to

students that the calculator is only a tool for them to use. The students must

know the operations of mathematics for the calculator to correctly perform the

arithmetic. This allows the students more time to learn and become comfortable

in applying principles of mathematics to problems and opportunities they

encounter in the real world.

**Performance Assessment**:

a. Give students a set of 20 problems that include parentheses,

exponents, multiplication, division, addition and subtraction.

b. Have students work the set of problems without the use of calculators.

c. Have students use the calculator to work the same set of problems.

d. Compare the scores on the two sets of problems.

e. Have students discuss advantages and disadvantages of using calculators

in class.

**Multicultural Application**:

Calculators and real numbers can be used efficiently by all cultures. Wise use

of the calculator as a tool can expedite mastery of new subjects and material in

mathematics.

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