Weigh It, Pour It – Class 4 Maths Chapter 8 Notes & NCERT PDF

Class 4MathematicsChapter 8NCERT book: Maths Mela - Class 4

Notes and a simple summary of Chapter 8 of the NCERT Class 4 Mathematics book, with the official chapter PDF, flashcards, an MCQ quiz and an AI tutor for your doubts.

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Chapter 8: Weigh It, Pour It

Introduction

"Weigh It, Pour It" builds on what children learnt in Grade 3 about the 1 kilogram salt packet and the 1 litre bottle. It opens with simple questions: arrange animals from heaviest to lightest, name the heaviest object at home, and think about whether the school bag feels light or heavy. The chapter then moves from weight (kilograms and grams) to capacity (litres and millilitres), and ends with a message about saving water.

What's in this Chapter

Fun at the Vegetable Market – Rita and Shabnam watch a vegetable seller weigh vegetables. Children guess the weight of half a pumpkin, then estimate whether 6 bananas, 5 potatoes, 10 tomatoes and 15 onions weigh less or more than 1 kg, and check on a weighing balance.

Grams and kilograms – We write kg for kilogram and g for gram. The book shows:

  • 2 packets of 500 g = 1000 g = 1 kg, so 500 g = 1/2 kg
  • 4 packets of 250 g = 1000 g = 1 kg, so 250 g = 1/4 kg
  • 10 packets of 100 g = 1000 g = 1 kg
  • Two 250 g daal packets balance one 500 g packet. Using 10 g erasers: a 50 g haldi packet = 5 erasers, a 100 g soap = 10 erasers, 250 g sugar = 25 erasers.

    Boxes of Sweets – Mr Shrinathan packs 1 kg Kaju-katli: 2 boxes of 500 g, 4 boxes of 250 g, 10 boxes of 100 g or 20 boxes of 50 g.

    Heavy and light – Taran and his sister lift packets of flour, rice and salt. Children estimate weights, count 1 kg packets in 10 kg, 20 kg, 50 kg and 25 kg, and match objects like a cat, an elephant, a pen and a leaf with sensible weights. The "Do You Know?" box tells us that weightlifter Mirabai Chanu won silver at the 2020 Tokyo Olympics in the women's 49 kg event, lifting a total of 202 kg.

    Measuring capacity – We write l for litre and ml for millilitre. 1000 ml = 1 l, so two 500 ml bottles fill 1 l (500 ml = 1/2 l) and four 250 ml bottles fill 1 l (250 ml = 1/4 l). Children use 10 ml dosing cups (100 of them fill 1 l) and 1 ml droppers (10 of them fill a 10 ml cup). Mr Krishna packs 1 l of perfumed oil as 2 bottles of 500 ml, 5 of 200 ml, 10 of 100 ml or 20 of 50 ml.

    Water Conservation – Put a container under a dripping tap for one hour. How much water is lost in an hour, a day, a week?

    Key Ideas

  • Weight is measured in kilograms (kg) and grams (g); 1 kg = 1000 g.
  • Capacity is measured in litres (l) and millilitres (ml); 1 l = 1000 ml.
  • Half of 1000 is 500 and a quarter of 1000 is 250, so 500 g = 1/2 kg and 250 ml = 1/4 l.
  • Light things (a pen, a leaf) are measured in grams; heavy things (a gas cylinder, an elephant) in kilograms.
  • Estimating first and then measuring makes us better at guessing.
  • Activities from the Book

  • Estimate-then-weigh table for fruits and vegetables.
  • Arrows showing which side a pan balance will tilt.
  • Monthly use of atta, rice, pulses and sugar at home.
  • Estimate and measure the capacity of a bottle, glass, mug, jug, bucket, teaspoon and bowl.
  • Visit shops to list items sold in 50 ml, 100 ml, 200 ml, 250 ml, 500 ml and 900 ml packs.
  • Words to Learn

  • Weight – how heavy something is (भार / वज़न)
  • Kilogram (kg) – 1000 grams (किलोग्राम)
  • Gram (g) – small unit of weight (ग्राम)
  • Capacity – how much a container can hold (धारिता)
  • Litre (l) – 1000 millilitres (लीटर)
  • Millilitre (ml) – small unit of capacity (मिलीलीटर)
  • Balance – scale with two pans (तराज़ू)
  • Estimate – a thoughtful guess (अनुमान)
  • Dropper – tool that gives 1 ml drops (ड्रॉपर)
  • Conservation – saving something (संरक्षण)
  • Tips for Parents & Teachers

  • Let children hold a 1 kg packet and a 500 g packet side by side.
  • Read labels on packets at home: which say g, kg, ml or l?
  • Fill a 1 litre bottle using a 250 ml glass and count the pours.
  • Do the dripping-tap experiment together and talk about saving water.
  • Common Mistakes

  • Thinking a bigger object is always heavier (a big pillow can be lighter than a small stone).
  • Mixing up weight units (g, kg) with capacity units (ml, l).
  • Forgetting that 1 kg is 1000 g, not 100 g.
  • 💡 Key Learning Points

    • ✓1 kg = 1000 g and 1 l = 1000 ml.
    • ✓500 g = 1/2 kg and 250 g = 1/4 kg; the same fractions work for 500 ml and 250 ml of a litre.
    • ✓Choose grams or kilograms (millilitres or litres) depending on how big the quantity is.
    • ✓Estimate first, then measure with a balance or measuring bottles to check.
    • ✓Water is precious – measuring leaks shows how much is wasted.

    👨‍🏫 Teaching Tips

    • →Bring a simple pan balance or kitchen scale and real packets (100 g, 250 g, 500 g, 1 kg).
    • →Play 'guess the weight' with fruits and vegetables before weighing them.
    • →Use empty bottles of 1 l, 500 ml, 250 ml and 100 ml for pouring games.
    • →Link 1/2 and 1/4 to the Fractions chapter: 500 is half of 1000.
    • →Ask children to collect wrappers showing g, kg, ml and l.
    • →Do the dripping-tap experiment for one hour in class.
    • →Connect to sports: talk about Mirabai Chanu and weight categories.

    📋 Assessment Questions

    1. Can the child say how many grams are in 1 kg and millilitres in 1 l?
    2. Can the child pick the right unit for an object (pen → g, gas cylinder → kg)?
    3. Can the child find how many smaller packets or bottles make 1 kg or 1 l?
    4. Can the child estimate and then check a weight or capacity?