TERM – 2ND TERM
WEEK FOUR
Class: Senior Secondary School 1
Age: 15 years
Duration: 40 minutes of 5 periods each
Date:
Subject: Technical Drawing
Topic: PLAIN SCALES
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
I.) Define plain scale
II.) Discuss the uses of plane scale.
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,
INSTRUCTIONAL PROCEDURES
PERIOD 1-2
PRESENTATION |
TEACHER’S ACTIVITY |
STUDENT’S ACTIVITY |
STEP 1 INTRODUCTION |
The teacher explains the meaning of plane scale to the students |
Students listens attentively to the teacher |
STEP 2 EXPLANATION |
Teacher discusses the uses of plane scale using the scale tool. |
Students exhibit attentiveness and active engagement |
STEP 3 NOTE TAKING |
The teacher writes a summarized note on the board |
The students copy the note in their books |
NOTE
PLAIN SCALES
A plain scale, also known as a linear scale, is a measuring tool used in technical drawing, engineering, architecture, and other fields. It consists of a straight line divided into evenly spaced increments, each representing a specific unit of measurement, such as inches, centimeters, or millimeters.
The term scale also refer to the ratio of the size of a drawing to the size of the actual object. The ratio or fraction is called the representative fraction of the scale.
The Representative fraction (R.F) = distance or size represented.
The following are the common used RF:
1:1 Full size image
1:2 Half full size
1:5 One - fifth full size
1:10 One - tenth full size
5:1 Five times the full size
Uses of plain scales
The primary uses of plain scales include:
EVALUATION: 1. What is a plane scale
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively