I.Learning Objectives

Cognitive :Solve mentatlly 1-step word problems involving addition with sums up to 100 without regrouping Psychomotor:Write an equation correctly

Affective:Show speed and accuracy in solving problem mentally

II. Learning Content

Skill:Mental computation 1-step word problems involving afddition

References:BEC PELC 1.B.2.2

Materials:Teaxtbook, flashcards, manila paper

Speed and accuracy

Speed and accuracy

Value:

III. Learning Experiences

A. Preparatory Activities

1. Drill – Add mentally (use flashcard)

89473

+3 +6 +5 +5 +9

2. Review

(Recall the steps in solving word problems involving addition) Group the pupils into 4 teams. Each team will analyze the word problem then let them answer the questions. Chona has 35 stamps. Her friend gives her 49 more. How many stamps does she have in all? *What is asked?

*What are given?

*What are the word clues?

*What process should be used?

*Write the number sentences?

*Solve the problem.

3.Motivation

Present problem opener

Chito was arranging the social hall for the Grade 3 program. He arranged 60 chairs in rows. Then he arranged 40 more chairs in rows. How many chairs did he arrange altogether?

B. Developmental Activities

1. Presentation

a. Let us solve the problem using POLYA’s 4step in problem solving.

Trivia: George Polya is thefather of Problem Solving. He listed 4 simple steps to use when solving any given problem. These are: UNDERSTAND – PLAN – SOLVE – LOOK BACK Trivia: George Polya is thefather of Problem Solving. He listed 4 simple steps to use when solving any given problem. These are: UNDERSTAND – PLAN – SOLVE – LOOK BACK

a.) Understand What are given? 60 chairs and 40 chairs

What is being asked? How many chairs in all?

What operation will solve the problem? Addition

b.) PlanWhat equation will solve the problems?

60 40 = n

c.) Solve* Lead students to notice that the addends end in 0. The

tens digits add up to 10.

*This equation maybe solved mentally by simply adding

the tens digits and annexing a 0.

60

+40

100

d.) Look BackDoes the answer make sense? Yes

What is the correct label? 100 chairs

* Stress accuracy and speed

b. Divide the class into 4 teams. Solve the problems that the teacher will

read. Write your answer in the “Show me Board”. The group with more points wins the game.

Give the sum of the following:

a) 10 straws and 20 bottle caps

b) 20 stones; 10 sticks and 10 marbles

c) 50 straws and 30 bottle caps

d) 40 sticks and 10 bottle caps

e) 20 marbles; 10 sticks and 20 stones

Were you be able to give the sum at once without using pencil and paper? Why?

2.Guided Practice

a.) Work in groups of four. Give each group a show-me –board. Solve mentally the problem written on a chart.

1. Edna bought 12 red roses and 12 white roses. How many roses did she buy in all? 2. Mary collected 50 shells last Saturday and 60 more last Sunday. How many shells did she collect in all? 3. Mang Andres harvested 95 cavans in July. In August he harvested 65 cavans. How many cavans of palay did he harvest altogether? 4. A fisherman caught 80 fish in the morning and 55 fish in the afternoon. How many fish did he catch in all? 5. Nelda picked 75 guavas while Yolly picked 25 guavas. How many guavas did they pick altogether?

b.) Work in groups of 8.

Play “Aim High”. Each group ill be given strips of colored papers. Group I – redGroup 3 – blue

Group 2 – yellowGroup 4 – orange

The teacher will post a problem on the board. Pupils read the problem silently. The first group who ill give the correct answer will have a chance to paste the strips of colored paper on the ladder. Repeat the same procedure until a group reach the top.