Unit 9. Decimals, fractions, and percents.
(conversion guide)
The Construction Assistant:
Converting Decimals, Fractions, and Percents
1. Reducing Fractions: Divide the numerator and denominator by the same number. Repeat if necessary until both cannot be divided into whole numbers.
2. Percentages: A percent is a fraction. Its denominator is 100. So 71% is equal to 71/100. In decimal form, this is 0.71. It is usually easier to do calculations with decimals instead of fractions. Convert measurements that are fractions to decimal form.
3. Convert a fraction to a decimal: Divide the numerator by the denominator.
4. Convert a mixed number to a decimal: First, write the whole number. Place a decimal point to its right. Change the fraction to a decimal (see above). Then write it to the right of the decimal point.
1. Before you read the passage, talk about these questions.
1. What are some ways of showing numbers that are not whole?
2. What is ½ displayed as a percent?
Reading
2. Read the guide about converting fractions, decimals, and percents. Then, mark the statements as true (T) or false (F).
1. _ Divide the numerator and the denominator to reduce a fraction.
2. _ The denominator of any percent is 100.
3. _ Divide the denominator by the numerator to convert a fraction to a decimal.
Vocabulary
3. Match the words (1-5) with the definitions (A-E).
1. _ numerator
2. _ fraction
3. _ percent
4. _ whole number
5. _ denominator
A. a number that is not divided into parts
B. the lower number of a fraction
C. a ratio of two numbers, expressed with one number written above the other
D. the upper number of a fraction
E. a number that expresses a part of something per hundred
4. Fill in the blanks with the correct words and phrases from the word bank.
Word Bank
decimal, convert, percentage, reduce, mixed number
1. The expression 12 2/3 is a __________.
2. __________ that fraction to its simplest terms.
3. What __________ of the insulation is installed?
4. Please ___________ that fraction to a decimal.
5. __________ numbers are usually more accurate that fractions.
5. Listen and read the guide about converting fractions, decimals, and percents again. How do you convert a fraction into a decimal?
Listening
6. Listen to a conversation between a construction worker and a manager. Choose the correct answers.
1. What is the conversation mainly about?
A. reducing a fraction
B. working with mixed numbers
C. comparing decimals and fractions
D. converting a fraction to a decimal
2. How should the man write the result?
A. as a whole number
B. as a decimal
C. as a mixed number
D. as a percent
7. Listen again and complete the conversation.
Worker: I 1 ______ ______ ______ this. How do you convert a fraction to a decimal?
Manager: Ah, where are you 2 ____________?
Worker: Well, you 3 ______ __________ by the numerator,right?
Manager: No, you divide 4 ______ _______ by the denominator.
Worker: Oh, I see. That makes a lot 5 ___________. Thanks for the help.
Manager: You`re welcome. I 6 _________ with those, too.
Speaking
8. With a partner, act out the roles below based on Task 7. Then, switch roles
USE LANGUAGE SUCH AS:
I can never remember _
No, you _
That makes a lot _
Student A: You are a construction worker. Talk to Student B about:
· doing a conversion calculation
· correcting a mistake
Student B: You are a manager. Talk to Student A about doing a conversion calculation.
Writing
9. Use the guide and the conversation from Task 8 to complete the email.
Converting fractions
Hi ________.
You made a mistake on your conversion. You _______ ________. But you`re supposed to _______. Please remember this for next time. Thanks, _______.
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