Converting Fractions to Decimals and Percents

The columns on a spreadsheet are useful in showing students how fractions relate to decimals and percents. They are just another way of describing the same number. This exercise illustrates how fractions are expressed as decimals and percents by having students record how they spend their time during different parts of the day. The activity will also enable students to see how a pie chart can be a useful representation of daily activities.

Classroom Discussion and Activities

Computer Lab Activities

Classroom Discussion and Activities (Whole Group)

Discuss with the students how the day can be broken up into 24 hours. Furthermore, the time spent sleeping, eating, going to school, etc., can be expressed as fractional parts of the day. In this activity, 24 will be used as the denominator in all of the fractions. If the student sleeps 8 hours, then the fractional part of the day spent sleeping is 8/24.

• Students may build a data table of the information using the Day.doc worksheet. This worksheet will enable students to record how many hours they spend doing each of their daily activities. Make sure the students use full hours and not minutes. Using minutes will only be confusing for the students.
• Make a fraction for each activity category in the day.
• Convert fraction numbers to decimals and percents using a fractions calculator.

In the Lab (Individual or Paired Work)

Create a spreadsheet using the students' data from their Day.doc worksheet.

• Type in the data for the hours column and the total day column.
• Format the fractions column using the FORMAT and then CELLS menu options. Make sure this column is formatted for fraction numbers.
• Copy the fractional numbers into the decimals and percent columns. Use the FORMAT and CELLS menu options to convert the decimals column to decimals and percent column to percents.
• Use the SUM function to compute the fraction, percent, and decimal columns.

Ask students some of the following questions: "Why would you not sum column C?" "Why is the sum of Column D equal to 1? " "Why is the sum of Column E equal to 100%?"

The table below shows an example of a student's completed spreadsheet.

 

• Compare their paper copy to the spreadsheet and identify errors.
• Make a pie chart and interpret results. Follow the directions in the Pie Charts document.
• Interpret results by asking questions such as: "Which is your biggest slice of pie?" "What percent is that slice?" "Which is your smallest slice of pie?" "What percent is that slice of pie?"