🍎 Apple or 🍌 Banana?
Weight: How heavy something is compared to another object
Heavier: An object that pulls down more on a scale
Lighter: An object that pulls down less on a scale
- Look at the objects carefully
- Think about their size and material
- Compare with things you know
- Make an educated guess
Bananas are usually longer than apples, so they might be heavier
A typical banana weighs about 120g while an apple weighs about 150g
Actually, apples are usually heavier than bananas of average size
The apple is heavier than the banana
• Size doesn't always equal weight: Small dense objects can be heavier than large light ones
• Material matters: Different materials have different densities
• Experience helps: Think about what you've felt before
Left side: 📚 Book
Right side: 🖊️ Pencil
Which side goes down?
Balance Scale: A tool that shows which object is heavier by tilting toward it
Heavier side: Goes down on the scale
Lighter side: Goes up on the scale
Left: Book (usually made of paper, cardboard, binding)
Right: Pencil (light wood/carbon)
A book typically weighs much more than a pencil
The heavier object makes its side go down
The left side with the book goes down
• Balance scale principle: Heavier objects make their side go down
• Relative weight: Compare objects based on material and size
• Visual cues: Look for obvious differences in size/mass
🦆 Rubber Duck, 🧸 Teddy Bear, 📦 Toy Box
Ordering by weight: Arranging objects from lightest to heaviest (ascending) or heaviest to lightest (descending)
Ascending order: Lightest → Heaviest
Descending order: Heaviest → Lightest
🦆 Rubber Duck: Small, hollow, made of soft plastic
🧸 Teddy Bear: Medium size, stuffed with cotton/other materials
📦 Toy Box: Large container, likely made of wood/plastic, can hold many toys
Rubber duck ≈ 50g, Teddy bear ≈ 200-500g, Toy box ≈ 1000g+
Lightest first: Rubber duck, then teddy bear, then toy box
From lightest to heaviest: Rubber Duck, Teddy Bear, Toy Box
• Systematic analysis: Consider size, material, and purpose of each object
• Logical ordering: Start with the most obvious extremes
• Verification: Check if the order makes sense
Weight: The measure of how heavy something is
Mass: Amount of matter in an object (affects weight)
Density: How tightly packed the material is
- Observe: Look at the objects carefully
- Compare: Think about size, material, and purpose
- Estimate: Use experience to guess weights
- Verify: Check with a scale if available
• Observation: Look at size, shape, and material
• Experience: Use past knowledge of similar objects
• Scale: Heavier side goes down on balance scale
• Ordering: Lightest to heaviest or vice versa
🥚 Egg or 🍞 Slice of Bread?
Estimation: Making an educated guess about weight without exact measurement
Comparison: Judging one object against another
Eggs are solid, contain liquid inside shell, relatively compact
Bread is porous, has air holes, less dense than egg
Egg ≈ 50g, slice of bread ≈ 30-40g
Egg is slightly heavier than a slice of bread
The egg is heavier than the slice of bread
• Material density: Solid objects often heavier than porous ones
• Structure: Air pockets reduce effective weight
• Experience: Think about handling these items
🐘 Elephant, 🐰 Rabbit, 🐶 Dog
Ranking: Ordering multiple objects by weight
Descending order: From heaviest to lightest
🐘 Elephant: Very large mammal, thick skin, heavy bones
🐶 Dog: Medium-sized pet, varies by breed
🐰 Rabbit: Small mammal, light bones, fluffy fur
Elephant: 2000-6000kg, Dog: 10-30kg (average), Rabbit: 1-3kg
Elephant >> Dog >> Rabbit
Order makes sense based on animal size and known weights
From heaviest to lightest: Elephant, Dog, Rabbit
• Size correlation: Generally larger animals are heavier
• Species knowledge: Use known facts about animals
• Logical ranking: Place extremes first, then middle values
Definition: Weight is how heavy something is. It measures how much force gravity pulls on an object.
Units: In 1st grade, we compare objects as heavy/light rather than using specific units.
Weight: How heavy something is compared to another object
Heavier: Pulls down more on a balance scale
Lighter: Pulls down less on a balance scale
Balance Scale: Shows which object is heavier by tilting toward it
Density: How tightly packed the material is (affects weight)
- Observe: Look at size, material, and structure of objects
- Compare: Think about what you know about similar objects
- Estimate: Make an educated guess about relative weights
- Verify: Use a balance scale or test by holding objects
• Density Rule: Objects with higher density are heavier for the same volume
• Material Rule: Metals > Wood > Plastic > Foam in general
• Structure Rule: Solid > Liquid > Gas in terms of weight per volume
• Size Rule: For same material, larger objects are generally heavier
• Balance Rule: Heavier side goes down on a balance scale