Lesson 36- Solving Routine or Non-routine Problems Involving Addition and Subtraction of Decimal Numbers Including Money Using Appropriate Problem Solving Strategies and Tools

Second Grading Period, Week 3

  1. Objective

Solve routine or non-routine problems involving addition and subtraction of decimal numbers including money using appropriate problem solving strategies and tools

Prerequisite concepts and skills:

Basic addition and subtraction facts

Basic concepts of addition and subtraction of decimals and steps in problem solving

Materials: charts, flash cards, chart of word problems activity cards

References: M5NS-IIc-108.1, LG Grade V p. 268-270, 21st Century mathematics p.68

LM Grade IV p 68-69

Instructional Procedures

  1. Preliminary Activities
  1. Drill

Have a drill on addition and subtraction of decimals using flash cards for 2 minutes only

  1. Review
  1. Check the assignment
  2. Review the steps in solving word problems.

Ask:What are the steps in solving a word problem?

In what steps will the following questions fall?

* What is asked?

* What are the given facts?

* What is the process to be used?

*What is the number sentence?

* Show the solution and complete answer.

  1. Motivation

Show a picture of a hill?

Ask: Have you been to a hill? What did you do there? Share some of your experiences.

Ask:Is it necessary to conserve our environment?

  1. Developmental Activities
  1. Presentation

Ask: What is asked in the problem?

What are given facts?

What word clue help you solve the problem?

What operation is to be used?

Ask a pupil to show his/her answer on the board.

  1. Performing the Activities

Solution:

2,968.78

+ 1,230.67

4,199. 4 5

Answer: So, 4, 199.45 total cost of seedlings planted by the Grades IV,V,VI pupils of Pook Elementary School.

Ask: Why do you think many pupils joined the tree-planting program?

What can you say about the pupils joined in the tree- planting program? What can you say about those who didi not join?

a. Values Integration

Ask:Is it necessary to conserve our environment? Why? How can you help conserve our environment?

  1. Performing the Activity

The pupils will form 3 groups and will be given a problem written on the bond paper. They are going to solve the problem and answer the questions on the problem.

Problem 1. Group 1

Jacob brought a pair of shoes for P245 a pair of sacks for P42.75 and trousers for P 526.99. He gave the cashier a thousand –peso bill. How much change did he receive?

a. What is asked?

b. What are the given facts?

c. What is the process to be used?

d.What is the number sentence?

e. Show the solution and complete answer.

Problem 2. Group 2

Mang Andrew has 8.25 kg. of tomatoes to sell in the market. In the morning he sold 4.75 kg. While he sold 2.25 kg in the afternoon.How many kg.of tomatoes were left?

a. What is asked?

b. What are the given facts?

c. What is the process to be used?

d.What is the number sentence?

e. Show the solution and complete answer.

Problem 3, Group 3

Last Saturday, Anna went to a bookstore and bought the following

items.: a pocket book which cost P 23.75; a set of colored pen which cost P 36.20 and

a liquid eraser which costP 23.95. If she gave P100-bill to the cashier, how much change did she receive?

a. What is asked?

b. What are the given facts?

c. What is the process to be used?

d.What is the number sentence?

e. Show the solution and complete answer.

Have a short discussion of their answers.

Ask: How did you solve the problem?

Let the pupils get their LM and study Explore and Discover on page of LM Math Grade V.

  1. Processing the Activities.

Ask: Which of the two problems is easier to solve?

In Which problem did you enjoy solving? Why?

How many operations did you use in solving problem1?2? What operation is it? How did you solve it? What is your number sentence? What is your final answer? Did you work with your group cooperatively? When your group solve the problem easily, how did you feel?

  1. Reinforcing the concept and skill

Say: Let us solve more problems.

Ask the pupils to work on the items under Get Moving LM Math Grade 5 page __ .

Check the pupils answer. For mastery, have them answer items under Keep Moving, LM Math Grade V page __. Check the pupils answer

  1. Summarizing the Lesson Lead the pupils to give the following generalization
  1. Applying to New and Other Situation

Ask the pupils to do items 1 to 5 under Apply your skills on page ____ of LM Math Grade V.

  1. Assesment

Solve the following problems.

Study the following menu in the canteen and answer the question that follows.

MENU

Spaghetti-P 23.75 / Gulaman-P6.00
Palabok -P21.50 / Nilaga(pork)- P22.50
Lugaw- P 8.50 / Pinakbet- P 15.00
Rice- P 5.00 / Fried Fish- P 12.00
Mango Juice-P7.50
  1. Arnel paid P 50.00 for pork nilaga and rice. How much was his change?
  2. Ayen ordered palabok and gulaman.How much was her change with her P 100 –bill.
  3. Mrs. Lopez ordered rice,pinakbet and fried fish. She gave P100. How much was her change?
  4. Kate gave P 50 for mango juice and spaghetti. How much is her change?
  5. It was Tina’s birthday. She ordered spaghetti, palabok, mango juice and gulaman. If she paid P100 peso-bill and she gave a tip of P 5.00 , how much will be her change?
  1. Home Activity

Solve the following problems.

  1. AJ earned P 35.50 in selling newspapers and he earned P32.50 for selling pandesal in the morning.He paid P 52.75 for a pad paper and a ballpen. How much money had he left?
  2. JM visits his dentist every six month. Hepaid his dentist P500 for dental treatment and P450 for prophylaxis. How much change did he get from P 1,000?

Enrichment:

Solve the problem and explain your answer