Class: Junior Secondary School 2 (JSS2, JSS 2)
Term: 1st Term
Week: 2
Age: 13 years
Duration: 45 minutes
Subject: Mathematics
Curriculum Theme: Mathematics
Previous Lesson: Standard
Topic: Approximation
Subject Matter: Approximation to a required degree of accuracy: tens, hundred, tenth etc., Approximation to decimal places, Approximation to significant figures.

Specific Objectives

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

Cognitive Domain:
(a) Identify different forms of approximation such as to the nearest tens, hundreds, decimal places, and significant figures.
(b) Solve problems involving approximation to specified degrees of accuracy.
Affective Domain:
(a) Develop accuracy and carefulness when rounding numbers.
Psychomotor Domain:
(a) Perform numerical approximations correctly using given figures.
Social Domain:
(a) Work cooperatively in groups to approximate numbers and compare results.

Reference Materials

The following resources was used in planning this lesson:

9 Years Basic Education Curriculum
Lagos State Unified Scheme of work for Junior Secondary Schools
Math Is Fun – “Rounding Numbers” (https://www.mathsisfun.com/rounding-numbers.html)
Relevant Textbooks

Instructional Materials

The teacher will teach this lesson with the aid of:

Place value chart
Number cards showing whole and decimal numbers
Flash cards with rounding rules
Whiteboard and markers
Chart showing examples of rounding to nearest tens, hundreds, and decimal places

Rationale for the Lesson

This lesson will help pupils develop skills in approximating numbers to make calculations simpler and results more meaningful in real-life and mathematical situations.

Prerequisite/Previous Knowledge

Pupils have already learned place values of numbers and can identify whole numbers and decimal numbers. They can also perform basic arithmetic operations confidently.

Lesson Content/Board Summary

Approximation

Approximation to the Nearest Tens, Hundreds, and Thousands

Approximation means expressing a number in a simpler form, close to its actual value. It helps to make calculations easier and quicker.

The following are rules for approximating numbers to the nearest tens, hundreds, or thousands:

Identify the digit at the place you are rounding to (tens, hundreds, etc.).
Check the next digit to the right.
If the next digit is 5 or more, increase the rounding digit by 1.
If the next digit is less than 5, leave the rounding digit as it is and change the digits after it to zero.

Examples include:

47 to the nearest ten = 50
364 to the nearest hundred = 400
7,846 to the nearest thousand = 8,000

Approximation to Decimal Places

Decimal approximation involves rounding a decimal number to a specific number of digits after the decimal point.

The following are steps for approximating to decimal places:

Identify the decimal place to which you want to round (e.g., tenth, hundredth).
Look at the next digit after that place.
If it is 5 or greater, increase the rounding digit by 1.
If it is less than 5, keep the rounding digit the same.

Examples include:

3.456 rounded to 2 decimal places = 3.46
8.731 rounded to 1 decimal place = 8.7
12.998 rounded to 2 decimal places = 13.00

Approximation to Significant Figures

Significant figures show the digits that carry meaningful information in a number. They help express accuracy in measurement and calculation.

The following are steps for approximating to significant figures:

Start counting significant figures from the first non-zero digit.
Identify the number of significant figures required.
Look at the next digit after the last significant figure.
If it is 5 or more, round up the last significant figure by 1.
If it is less than 5, keep it the same and change the rest to zeros (for whole numbers).

Examples include:

4,872 to 2 significant figures = 4,900
0.05326 to 2 significant figures = 0.053
129.6 to 3 significant figures = 130

Teaching Methods/Instructional Techniques:

Lecture, Explanation, Demonstration, Discussion, Group Work, Question and Answer, Practice Exercises

Instructional Procedures

To deliver this lesson, the teacher will adopt the following steps:

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher recalls the previous lesson on place value and introduces the topic “Approximation” by asking pupils why people often use round numbers in real life (e.g., price estimates).
Pupils’ Activity: Pupils respond and share examples where they use round numbers in daily life.
Learning Point: Pupils understand that approximation helps simplify numbers for convenience.

Step 2: Approximation to Nearest Tens and Hundreds

Time: 10 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains rounding to tens and hundreds using examples on the board and a place value chart.
Pupils’ Activity: Pupils follow the explanation and perform similar examples.
Learning Point: Pupils understand the rules for rounding whole numbers.

Step 3: Approximation to Decimal Places

Time: 10 minutes
Teaching Skill: Demonstration
Teacher’s Activity: The teacher demonstrates how to round numbers with decimals using real examples.
Pupils’ Activity: Pupils attempt exercises on rounding to decimal places.
Learning Point: Pupils learn how to approximate numbers correctly to required decimal places.

Step 4: Approximation to Significant Figures

Time: 10 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher defines significant figures and explains how to approximate to required significant figures using examples.
Pupils’ Activity: Pupils solve practice examples given by the teacher.
Learning Point: Pupils understand how to approximate using significant figures.

Step 5: Note-Taking

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher writes the board summary for pupils to copy.
Pupils’ Activity: Pupils copy the note neatly into their notebooks.
Learning Point: Pupils have a written record of the lesson content.

Step 6: Evaluation/Review

Time: 3 minutes
Teaching Skill: Questioning
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

State two rules of approximation.
Round 672 to the nearest hundred.
Round 5.768 to 2 decimal places.
Approximate 0.03458 to 2 significant figures.
Pupils’ Activity: Pupils answer the questions orally and in writing.
Learning Point: Pupils demonstrate understanding of approximation in various forms.

Step 7: Conclusion

Time: 2 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: The teacher summarizes the lesson and emphasizes accuracy when rounding numbers.
Pupils’ Activity: Pupils listen attentively and ask questions for clarification.
Learning Point: Pupils appreciate the use of approximation in simplifying numerical work.

Lesson Keywords

Approximation – expressing numbers close to their true value for simplicity
Rounding – changing a number to the nearest desired value
Decimal Place – position of a digit after the decimal point
Significant Figures – meaningful digits in a number that show precision
Accuracy – how close an approximate value is to the actual value

Differentiation

Teacher supports slower learners with simpler examples and step-by-step explanation, while advanced learners solve higher-level problems and assist peers.

Note for teachers using this lesson plan

Encourage pupils to check their results after rounding. Use real-life contexts like prices, distances, and measurements to make the lesson relatable.