Solving Backward

LC: Solve word problems by working backwards.

I. Learning Objectives: After the activity, pupils shall be able to

EOC1 solve word problems by working backwards.

EOP2 demonstrate accuracy in writing the equation

EOA3 solve with confidence.

II. Learning Content:

Topic: Working Backwards

Concept: When solving a problem by starting at the end and working

backwards, any mathematical operations you

come across will have to be reversed.

Skill: solving correctly

Values: confidence

Material: problems written in cartolina

Resources: www. lessonpage.com

MTG Pop Sheets

III. Learning Experience:

Classroom Routine: Checking of Attendance and I.D.

A. Introduction: Back Me Up!

Activity 1. Who can recite the alphabet backwards?

Activity 2: Who can write his name backward in 15 seconds?

· What comes to your mind when you hear the word

“backward”?

· In Math, is there an instance where in we solve backwards?

· What is the opposite of addition? multiplication?

B. Interaction: Pairwork

Activity 3:

Jimmy had a certain amount of money. He spent P54 on books

and received another P300 from his father. He then had P580 left.

How much did he have at first?

a. Can someone give an example of a word or words that imply addition or subtraction?

b. Can you state the ways you could solve a problem?

c. What have you noticed in the given problem?

d. How would you solve when the unknown is in the beginning of the problem?

e. What symbol do you represent for the unknown?

f. What do you think is the mathematical sentence?

Let X the amount he had at first

X – P54 + P300 = P580

X= P580 –P300 + P54 = P334

g. Is the answer reasonable?

C. Integration:

1. Generalization:

· When do we solve backwards?

· How do we solve backwards?

2. Evaluation: Quiz

a. N + 45 - 66 x 8 = 88, what is N?

b. Subtract 14 from a number, the result is 51. What is the number?

3. Reflection:

How can you gain confidence in solving problems?

IV. Assignment: Drill Notebook

I. Write an equation, then solve by working backwards.

There were some apples in a box. Tom took 15 apples and Janet took 27 apples out of the box. Mrs. Tan put in 20 more apples

and threw away 9 rotten apples. There were 60 apples left in the

box. How many apples were there at first?

II. Answer briefly.

Did you find difficulty in solving the problem?

Which word/phrase distracts you most?