Lesson Notes By Weeks and Term v3 - Primary 1
Weight
Download the Lessonotes Mobile Nigeria 2025 app for faster lesson access on Android and iPhone.
Weight
Download the Lessonotes Mobile Nigeria 2025 app for faster lesson access on Android and iPhone.
Subject: General Mathematics
Class: Primary 1
Term: 1st Term
Week: 11
Theme: Mensuration And Geometry Primary One
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
Watch on YouTubeCompare the weights of some common objects in the school using the terms light and heavy.
Concept 1: Weight Explanation: Weight describes how heavy or light an object is. It is the force by which gravity pulls an object towards the earth. For Primary 1, the concept is simplified to mean the "heaviness" of an object as perceived when lifted or felt.
Key Idea: All objects have weight, but some are heavier than others, and some are lighter.
Concept 2: Heavy Explanation: An object is described as "heavy" if it requires significant effort to lift or move. When compared to another object, the heavier object will exert more downward pull. Characteristics of Heavy Objects (Primary 1 level): Hard to lift. Feels substantial in hand. Often, but not always, larger in size (though size is not the sole determinant of weight, e.g., a small stone vs. a large feather). Nigerian Context
Examples: A full bucket of water, a bag of rice, a yam, a mortar (for pounding fufu), a school textbook.
Concept 3: Light Explanation: An object is described as "light" if it is easy to lift or move with minimal effort. When compared to another object, the lighter object will exert less downward pull. Characteristics of Light Objects (Primary 1 level): Easy to lift. Feels less substantial in hand. Often, but not always, smaller in size. Nigerian Context
Examples: A piece of paper, a feather, an empty plastic cup, a leaf, a small seed (e.g., a groundnut).
Concept 4: Comparison of Weights Explanation: Understanding "heavy" and "light" often involves comparing two or more objects. The terms "heavier than" and "lighter than" are used to express this comparison. Practical Method for Comparison (Primary 1): Direct Lifting: Students physically lift two objects, one in each hand, to feel the difference in effort required.
Verbal Description: Students use the terms "heavy," "light," "heavier than," and "lighter than" to describe their observations. Worked Examples (Descriptive, not calculative, for Primary 1): Example 1: Comparing a Textbook and a Pencil Teacher's Action: Hold a standard Primary 1 General Mathematics textbook in one hand and a pencil in the other.
Observation: The textbook requires more effort to hold up; the pencil is very easy to hold.
Conclusion: "The textbook is heavy. The pencil is light." "The textbook is heavier than the pencil." "The pencil is lighter than the textbook." Example 2: Comparing a Yam and a Groundnut Teacher's Action: Place a medium-sized yam on one side of a table and a single groundnut on the other.
Observation: The yam feels much more substantial and would require more effort to lift. The groundnut feels almost weightless in comparison.
Conclusion: "The yam is heavy. The groundnut is light." "The yam is heavier than the groundnut." "The groundnut is lighter than the yam." (Relating to common Nigerian food items).
Example 3: Comparing an Empty Water Bottle and a Full Water Bottle Teacher's Action: Present an empty plastic water bottle and an identical bottle filled with water.
Observation: The empty bottle is very easy to lift. The full bottle is noticeably harder to lift.
Conclusion: "The empty bottle is light. The full bottle is heavy." "The full bottle is heavier than the empty bottle." "The empty bottle is lighter than the full bottle." Materials: A variety of common classroom objects and everyday items with noticeable differences in weight, e.g., textbooks, notebooks, pencils, erasers, chalk, duster, small stones, leaves, empty water bottle, full water bottle, a small toy, a ruler, a school bag (empty and with a few books), a piece of yam, a mango, a feather, a small plastic spoon.
Introduction (5 minutes): Teacher Activity: Begin by holding up two very contrasting objects, e.g., a large stone and a feather, or a textbook and a small piece of chalk. Ask students simple questions that encourage them to think about effort, e.g., "Which one do you think is harder to lift?" "Which one feels like it wants to fall down faster?" Student Activity: Students observe the objects and offer initial responses based on their intuition.
Activity 1: Hands-on Exploration and Direct Comparison (15 minutes)
Teacher Activity: Distribute pairs of objects to small groups or have students pick pairs from a collection. Ensure one object in each pair is clearly heavier than the other.
Examples: (Textbook, eraser), (Full water bottle, empty water bottle), (Small stone, leaf), (School bag with books, empty school bag). Instruct students to physically lift one object in each hand simultaneously (if safe and practical for their age), or lift each object individually to feel its "heaviness." Model the use of comparative language: "This book is heavy, this chalk is light. So, the book is heavier than the chalk." Guide students to articulate their observations using the terms "heavy," "light," "heavier than," and "lighter than." Student Activity: Students handle the objects, lifting them and feeling their weights. Students verbally describe which object is heavy and which is light. Students practice using comparative language to describe their findings to their group members and to the teacher.
Activity 2: Sorting Objects by Weight (10 minutes)
Teacher Activity: Provide a collection of 5-7 varied objects (some clearly heavy, some clearly light). Draw two large circles on the board or provide two labelled containers: one labelled "HEAVY" and the other "LIGHT." Instruct students to take an object, feel its weight, and place it in the appropriate circle/container. Encourage discussion and justification for their placement.
Student Activity: Students take turns selecting an object, feeling its weight, and classifying it as "heavy" or "light." They place the object in the corresponding group. Students verbally explain their choices when prompted.
Activity 3: Everyday Scenarios and Verbalisation (10 minutes)
Teacher Activity: Present various real-life scenarios relevant to Nigerian contexts using words or simple drawings/pictures.
Examples: "A mother carrying a baby vs. the baby carrying a toy." "Someone carrying a basket of yam from the market vs. someone carrying a single orange." "A pupil carrying a lunch box vs. a pupil carrying a full school bag." Ask questions like, "Which one would feel heavier?" or "Which person is carrying something light?" Facilitate a class discussion, encouraging students to explain why one object is heavier or lighter in these scenarios.
Student Activity: Students listen to the scenarios and identify the heavier or lighter item/person. They use the terms "heavy" and "light" to respond to the questions and justify their answers based on their understanding.
Instructions for Teacher: Present these questions orally and/or visually with the actual objects or pictures. Allow students to physically compare or describe their experience with similar objects.
Question: Hold a small pebble and a piece of chalk. Which one is heavier?
Solution: The small pebble.
Commentary: Even though the chalk might be longer, the pebble is typically denser and requires more effort to lift, making it heavier than a standard piece of chalk.
Question: Look at a duster and a ruler. Which one is lighter?
Solution: The ruler.
Commentary: A standard classroom duster (especially wooden ones) is usually more substantial and requires more effort to lift than a thin plastic or wooden ruler.
Question: Imagine carrying a basket full of ripe mangoes from the market and carrying just one mango. Which load is heavier?
Solution: The basket full of ripe mangoes.
Commentary: Many mangoes together have a combined weight that is significantly greater than the weight of a single mango. This relates to real-life experiences in Nigerian markets.
Question: Pick up an empty plastic bottle and then pick up the same bottle filled with sand. Which one feels heavy?
Solution: The bottle filled with sand.
Commentary: The sand adds substantial weight to the bottle, making it much heavier than when it was empty. This demonstrates that content contributes to weight.
Remediation (for struggling learners): More One-on-One Guided Comparison: Provide very distinct pairs of objects (e.g., a brick vs. a sheet of paper) and guide the student physically through the comparison, ensuring they feel the weight difference. Use consistent, simple verbal cues: "This is heavy," "This is light." Focus on Single Term First: Teach "heavy" first, then "light," before combining them for comparison. Ask them to identify only "heavy" objects from a group, then only "light" objects.
Repetitive Practice with Familiar Objects: Use objects they interact with daily (pencil, book, ruler, shoe) to build confidence.
Peer Support: Pair a struggling learner with a more capable peer during hands-on activities, allowing them to learn through observation and direct interaction.
Extension (for high-achieving learners): Ordering by Weight: Provide three or more objects (e.g., a feather, a stone, a book) and challenge students to arrange them in order from "lightest to heaviest" or "heaviest to lightest" by physically comparing them.
Introducing a Simple Balance Scale: If available, demonstrate a simple seesaw-like balance scale. Show how placing a heavier object on one side makes it go down, while a lighter object on the other side goes up. This visual representation can deepen their understanding of comparative weight without formal measurement.
Creative Problem Solving: Ask students to identify two objects in the classroom, where one is heavier than a given object X but lighter than object Y. For example, "Find something heavier than an eraser but lighter than a chair."
Market Shopping (Community & Economy): Students can relate the concept of weight to buying goods at the local market. For instance, when buying food items like rice, beans, or garri, people often describe quantities in terms of "how heavy" they are (e.g., "a cup of garri," "a measure of beans"). They can understand why a large bag of yam is more expensive and harder to carry than a single tuber.
Household Chores (Daily Life): The concept applies to everyday tasks at home. Students can identify that a bucket of water fetched from the well or tap is heavier than an empty bucket, making it harder to carry. Moving furniture or helping to carry groceries from the car/bicycle involves understanding which items are heavy and require more effort. Agriculture and Farming (Environment & Economy): For children in rural areas, understanding weight is crucial when helping with farm work. They might observe adults carrying baskets of harvested crops (e.g., maize, cassava) and recognise that a full basket is very heavy, while a single ear of maize is light. This relates to the effort involved in farming and transporting produce.