WebQuest

WebQuest on Rate

Primary 5 Mathematics

Mrs. Theodora Tan, Miss Haslindah and Mrs. Cynthia Seto

Geylang Methodist Primary School

Introduction

A rate involves two quantities. It is expressed as one quantity per unit of another quantity. For example, when we say that a bottling machine fills bottles at the rate of 8 bottles per minute, we mean “the machine can fill up 8 bottles in 1 minute.”

When we say that water is flowing into a tank at the rate of 2 litres per minute, we know that for every minute, 2 litres of water is collected in the tank.

http://www.moe.gov.sg/edsoftware/ir/files/maths-p-rate-of-flow-v2/index.htm

The Task

You are a nutritionist with “Looking Good Fitness Centre” and your role is to counsel clients on the amount and type of food they should eat and the activities that they need. To provide good advice, you need to collect and analyze data about food and take into account the calories intake per day, the total calories gained or lost per week, the calories in 1 gram of food and the calories burned in 1 minute during an activity.

Your task is to design a weight loss programme for an 11-year old boy to help him achieve his preferred mass within 4 to 7 months.

· His height is 154cm. His present mass is 65 kg and he hopes to weigh 55 kg.

· His calorie intake per day (excluding the weekend ‘must-have’ extras) is

2300 calories.

· His Saturday snack consists of about 40 pieces of potato chips.

On Sunday, besides his normal meals, he will have either 2 pieces of chicken thighs (original recipe) and a small glass of coca-cola at KFC or 2 slices of Thin n Crispy Pizza (Supreme Topping) and a small glass of coca-cola at Pizza Hut for tea.

· At home, he will nap for 1 hour, spend 1 hour on homework and about 2

hours on computer games or watch television.

In the “Looking Good” weight loss proposal, you will need to include:

· His current weight profile and the extra calories

· A suggested time-frame to achieve his preferred mass

· A recommendation on the kinds of exercises to burn off the extra calories

The Process

With your shoulder partner, understand the task given, work it out carefully with your partner and record the responses in the activity sheet. Remember that both of you need to discuss before coming to a conclusion. These are the steps you should take to accomplish the task:

Activity 1: Analyse the problem

1. What is your client’s calories intake per day and his calorie requirement in a day? To check this, use the “Weight Profile” tool in the link below to key in all the necessary information (name, height, weight, age, gender).

http://www.nutrition.com.sg/ha/index.asp

http://www.nutrition.com.sg/he/herda-chd.asp

2. What is the amount of extra calories from potato chips, KFC Chicken, pizza and coca-cola?

calorie content in fast food:

http://www.nutrition.com.sg/do/dofastfood.asp

calorie content in potato chips:

http://kidshealth.org/kid/nutrition/food/calorie.html

3. What is the difference between his calories requirement and his total calories intake per week?

Activity 2: Goal Setting

4. If he stays at his current mass, how many calories must he reduce per day?

5. To achieve his desired mass, how many kilograms must he reduce?

Use the information below to work out the time required for him to lose weight safely.

To lose weight by 0.5 kg in one week, he must reduce his caloric intake by 500 calories per day or 3500 calories per week.

Activity 3: Your Proposal

6. What is the total amount of calories your client needs to reduce per day?

7. Food is not the only thing that affects weight; exercise or lack of it will affect the amount of calories burned. Emphasize to your client to focus on a proper diet and exercise to lose 10 kg. You may want to convince him of the followings:

Ø What if he replaces some of his computer games or nap with exercises? How many calories will be burned?

Ø What kind of exercise should he take and how long?

Ø How about reducing the amount of potato chip and fast food?

Ø How many calories will that be?

Ø How about reducing his caloric intake per day?

Exercise: http://www.nutrition.com.sg/ha/hagym.asp

Sports: http://www.nutrition.com.sg/ha/hasports.asp

Nap/computer games: (last paragraph of ‘How the Body

Uses Calories)

http://kidshealth.org/kid/nutrition/food/calorie.html

Fast Food: http://www.nutrition.com.sg/do/dofastfood.asp

Potato Chips: http://kidshealth.org/kid/nutrition/food/calorie.html

Write out your detailed plan with calculations for your client on the Fitness Proposal provided.

Evaluation

	Level 1	Level 2	Level 3	Level 4	Score
Understanding the task	Demonstrate little ability to select and process information to complete their task even after teacher’s intervention.	Demonstrate little ability to select and process information to complete their task.	Demonstrate some ability to select and process information to complete their task.	Demonstrate full ability to select and process information to complete their task.
Mathematical Concept of Rate	Pupils are somewhat able to show that the units of calories burnt correspond to the unit of time with less than 50% accuracy.	Pupils are somewhat able to show that the units of calories burnt correspond to the unit of time with at least 50% accuracy.	Pupils are able to show that the units of calories burnt correspond to the unit of time with at least 75% accuracy.	Pupils are able to show that the units of calories burnt correspond to the unit of time with at least 90% accuracy.
Realistic Recommendation	Considers some factors but proposal does not satisfy the given conditions.	Considers some factors and able to provide a proposal that satisfies the given conditions.	Considers all factors and provides a balanced but vague proposal.	Considers all factors and able to provide a balanced and detailed proposal.

Conclusion

Congratulations! You have completed your task and together with your partner, both have you have managed to put up a fitness proposal for your client. If you have any questions about this lesson, you are invited to post your comment to me.

Now that you have learned how to interpret a rate as one quantity per unit of another quantity, it’s good to extend your learning by finding out more about rate used in our everyday life by visiting these websites:

Postage Rate

http://www.singpost.com.sg/quick_services/quicks_03postal.htm

Taxi fare

http://www.comfort-transportation.com.sg/rates_charges.html

Mobile Phone Rate

http://home.singtel.com/consumer/products/mobile/price_plans/overview_overview.asp

Learn to calculate water bill

http://www.pub.gov.sg/info_center/IcFfWaterTariffs.aspx?l1=4&l2=22&l3=27

http://www.pub.gov.sg/conservation/ConservWaterConsumpCalc.aspx?l1=3&l2=15

http://www.pub.gov.sg/info_center/IcEduTeachersKitMenu.aspx?l1=4&l2=22&l3=31