Mathematics - Junior Secondary 1 - Approximation

Approximation

Get it on Google Play
Get it on the Apple App Store
  1. Home
  2. Comprehensive Lesson Plan and Notes
  3. Junior Secondary 1
  4. Approximation

TERM: 2ND TERM

WEEK 1

Class: Junior Secondary School 1
Age: 12 years
Duration: 40 minutes of 5 periods
Subject: Mathematics
Topic: Approximation
Focus: Rounding Numbers & Degrees of Accuracy

SPECIFIC OBJECTIVES:

By the end of the lesson, pupils should be able to:

  1. Understand the concept of approximation and its usefulness.
  2. Round numbers to the nearest whole number, tens, hundreds, and thousands.
  3. Identify and use significant figures and decimal places.
  4. Determine the degree of accuracy of given numbers.
  5. Apply approximation in real-life situations.

 

INSTRUCTIONAL TECHNIQUES:

  • Question and answer
  • Guided discovery
  • Individual and group work
  • Real-life application
  • Drill and practice

 

INSTRUCTIONAL MATERIALS:

  • Number lines
  • Flashcards
  • Place value charts
  • Charts showing rounded figures
  • Worksheets
  • Whiteboard and markers

 

PERIOD 1 & 2: Introduction to Approximation & Rounding Numbers

PRESENTATION:

Step

Teacher’s Activity

Pupil’s Activity

Step 1 - Introduction

Explains what approximation is and its importance in daily life.

Pupils listen and participate

Step 2 - Explanation

Demonstrates how to round to the nearest 10, 100, and 1,000.

Pupils observe and ask questions

Step 3 - Demonstration

Uses number line and flashcards to round examples (e.g., 47 ≈ 50).

Pupils round different examples

Step 4 - Note Taking

Teacher writes key notes and rules on rounding on the board.

Pupils copy and practice

NOTE ON BOARD:

  • If the digit is 5 or more, round up. If less than 5, round down.
  • 84 rounded to nearest ten = 80
  • 1,473 rounded to nearest hundred = 1,500
  • 56,732 rounded to nearest thousand = 57,000

EVALUATION (5 exercises):

  1. Round 25 to the nearest ten
  2. Round 145 to the nearest hundred
  3. Round 8,999 to the nearest thousand
  4. Round 999 to the nearest hundred
  5. Round 3,495 to the nearest hundred

CLASSWORK (5 questions):

  1. 67 (nearest 10)
  2. 849 (nearest 100)
  3. 7,198 (nearest 1,000)
  4. 4,321 (nearest 100)
  5. 158 (nearest 10)

ASSIGNMENT (5 tasks):

  1. Write 5 numbers of your choice.
  2. Round each to the nearest 10.
  3. Round each to the nearest 100.
  4. Round each to the nearest 1,000.
  5. Explain why rounding is useful in real life.

 

PERIOD 3 & 4: Decimal Places and Significant Figures

PRESENTATION:

Step

Teacher’s Activity

Pupil’s Activity

Step 1 - Introduction

Reviews rounding to whole numbers. Introduces decimal places and significant figures.

Pupils recall and listen

Step 2 - Explanation

Demonstrates rounding decimals and identifying significant figures.

Pupils ask questions and practice

Step 3 - Demonstration

Works through examples like 3.145 → 3.15 (2 d.p), and 407 → 3 s.f.

Pupils solve problems with guidance

Step 4 - Note Taking

Summarizes rules for significant figures and decimal places.

Pupils copy and apply

NOTE ON BOARD:

  • Decimal places: number of digits after the decimal point.
  • Significant figures: count from the first non-zero digit.
  • Example:
    • 3.4567 → 3.46 (2 d.p)
    • 0.00567 → 3 s.f = 0.00567

EVALUATION (5 exercises):

  1. Round 3.987 to 2 decimal places
  2. Round 7.89654 to 3 significant figures
  3. Round 0.0345 to 2 s.f
  4. Round 6.999 to 1 decimal place
  5. Identify 2 s.f in 0.00456

CLASSWORK (5 questions):

  1. 6789 (2 d.p)
  2. 07654 (2 s.f)
  3. 5004 (3 s.f)
  4. 899 (1 d.p)
  5. 00678 (2 s.f)

ASSIGNMENT (5 tasks):

  1. Pick any 5 numbers with decimals.
  2. Round them to 2 decimal places.
  3. Identify the first 2 significant figures.
  4. Explain the difference between s.f and d.p.
  5. Create your own 2 examples each for s.f and d.p.

 

PERIOD 5: Degree of Accuracy

PRESENTATION:

Step

Teacher’s Activity

Pupil’s Activity

Step 1 - Introduction

Explains that approximation can depend on degree of accuracy required.

Pupils listen and respond

Step 2 - Explanation

Discusses different accuracy levels in real life: shops, science, sports, etc.

Pupils give real-life examples

Step 3 - Drill

Pupils try rounding and stating degree of accuracy in word problems.

Pupils solve problems independently

EVALUATION (5 questions):

  1. What is the degree of accuracy in 3.46?
  2. What is the degree of accuracy in 5.00?
  3. Round 10.456 to 1 decimal place
  4. What is the 2 s.f of 0.00712?
  5. Write 3.14159 to 3 decimal places

CLASSWORK (5 tasks):

  1. Explain degree of accuracy.
  2. Identify accuracy in 78.00
  3. Round 4.789 to 2 d.p
  4. Round 0.0891 to 2 s.f
  5. What are the 3 significant figures of 3400?

ASSIGNMENT (5 tasks):

  1. Find 3 measurements from a cooking book or newspaper.
  2. Identify the degree of accuracy in each.
  3. Round each to 2 decimal places.
  4. Give 2 significant figures for each.

Explain what the accuracy means in each case.