Fractions / Decimals - Lesson 3.9

Written by: Suzy Giorgione

GOAL / Learning Outcomes: Students will gain an understanding of fractions and

decimals and apply this knowledge to show how to switch a number between the two formats.

Target Grade Level: Sixth grade advanced

Time frame: 1 or 2 - 45 minute lessons

Sunshine State Standards: MA.A.1.3.2, MA.A.1.3.4

Prerequisite skills (Student): Students should be able to turn a fraction from

mixed to improper format and back. Students should know how to do long division. Students should have an understanding of rounding, decimal place values, and simplifying fractions.

Prerequisite skills (Teacher): Teacher should have working knowledge of power

point, basic knowledge for using a wireless laptop system, and have knowledge using Geogebra files.

Materials: Paper

Pencil

Wireless laptops for the class

Overhead projector (for power-point presentation)

Fractions/Decimals.ppt

Fractions/decimals.ggb.html

jmatchtest.htm

Key Words: Bar notation, Decimal, Denominator, Fraction, Improper fraction, Mixed number, Numerator.

Procedure:

·  Begin with a brief review for how to turn an improper fraction into a mixed number – and – a mixed number into an improper fraction. I have provided for a short warm up in the power point – including two from mixed to improper and two from improper to mixed. Each have a small (fun) reminder for how to achieve the correct answer.

·  Next explain to the students that decimals, fractions, and percents for that matter are all different formats for writing numbers. Let them know that they will focus on fractions and decimals today. Tell them that they will begin by learning how to turn a fraction into a decimal. I usually talk about hockey for a little bit to get the students interest and then I tell them that the division box is really a “penalty box”. I show them that to turn a fraction into a decimal they must divide the numerator by the denominator…this means that the top number always gets caught and thrown into the penalty box. I remind the students – after they place the number into the penalty box – before dividing – bring up the decimal and add a few zeros (this way they won’t forget this later when they are thinking about their division).

·  Once the students have the basic idea down – a few things must be addressed so that the students know how to write their answers. The next slide focuses on repeating decimals – and how to place the bar notation over the numbers that will repeat forever. The slide that follows this allows the students to try three problems on their own. Remember to allow enough time for the students to do their work on their own before showing the answers.

·  Now is a good time to remind students that they will sometimes have to round their answer. Go over the steps for rounding a decimal. Tell the students – if the instructions say to round their answer to the nearest hundredth…that the answer should only have two digits to the left of the decimal (because this is the hundredths place value). Let them know that the digit in the thousandths place value decides whether the digit before it goes up or stays the same. I did not put in a slide reviewing rounding – this should be review for the students.

·  The next slide explains how to write a decimal as a fraction. Usually these steps are easier for the students. You will have to remind the students to simplify the fraction at the end if necessary. Prompt them to use their divisibility tests to see if the two numbers can be simplified.

·  The last slide tells how to compare and order numbers. The students usually are able to start out correctly – turning every number into either a decimal or a fraction it doesn’t matter which way they go as long as they are all the same. They may need a small reminder about how to compare fractions (I teach this by cross multiplying upwards). Students often times forget – once they placed them in order – to rewrite their list in the original format that it was given.

·  After the Power-point you can have the students pull up the Fractions/Decimals.ggb.html file so that the students can explore a fraction into a decimal – and they can see how when the numerator and denominator change – the decimal changes. Encourage students to play with the sliders and explore the answers to the questions below the interactive portion of the worksheet. Ask student to find the decimal equivalent of several fractions…you can challenge students by asking them to find a fraction equivalent to a particular decimal.

·  The final part of the lesson is the jmatchtest.htm This is a mini quiz designed so that students can try to match up 10 fractions with their equivalent decimals within a five minute time period.

·  Throughout the lesson you should stress that a fraction and a decimal can represent the same values and the way the value is written is just a matter of format. This idea allows students to relax a bit while working with fractions.