Solved Exercises on Testing Weights in Grade 2

Master weight comparison: light vs heavy objects, using scales, ordering by weight, estimation skills through these 5 detailed exercises.

Solution: Exercises 1 to 3
1 Comparing weights
Exercise 1
Which object is heavier?
🍎 Apple (150g) vs 🍌 Banana (120g)
Circle the heavier object.
Definition:

Weight: How heavy something is. Heavier objects have more weight than lighter ones.

Comparison method:
  1. Look at the weight numbers given
  2. Compare the numbers using greater than (>) or less than (<)
  3. The object with the bigger number is heavier
🍎 Apple
150g
>
🍌 Banana
120g
Step 1: Identify the weights

Apple weighs 150 grams, Banana weighs 120 grams

Step 2: Compare the numbers

150 > 120, so the apple is heavier than the banana

Step 3: State the answer

The apple is heavier than the banana

🍎 Apple (150g) is heavier than 🍌 Banana (120g)
Final answer:

The apple is heavier because 150g > 120g

Applied rules:

• Greater than: When comparing weights, the larger number means heavier

• Units: Always compare weights with the same unit (grams, pounds, etc.)

• Comparison: 150g > 120g, so apple is heavier

2 Using a balance scale
Exercise 2
Look at the balance scale:
Left side: 🐘 Elephant toy (500g)
Right side: 🦊 Fox toy (300g)
Which side goes down?
Definition:

Balance scale: A tool that shows which object is heavier. The heavier side goes down.

🐘 Elephant toy
500g
>
🦊 Fox toy
300g
Step 1: Identify the weights

Elephant toy weighs 500g, Fox toy weighs 300g

Step 2: Compare the weights

500g > 300g, so the elephant toy is heavier

Step 3: Determine which side goes down

On a balance scale, the heavier side goes down

The left side (elephant) goes down
Final answer:

The left side goes down because 500g > 300g

Applied rules:

• Balance scale rule: Heavier objects make their side go down

• Comparison: 500g > 300g, so elephant side goes down

• Visual indicator: Downward tilt shows heavier weight

3 Ordering by weight
Exercise 3
Order these objects from lightest to heaviest:
🚗 Car toy (200g)
🏠 House toy (400g)
🐰 Rabbit toy (150g)
Definition:

Ordering: Arranging objects from smallest weight to largest weight (lightest to heaviest)

🐰 Rabbit
150g
<
🚗 Car
200g
<
🏠 House
400g
Step 1: List all weights

Rabbit: 150g, Car: 200g, House: 400g

Step 2: Compare all weights

150g < 200g < 400g

Step 3: Arrange from lightest to heaviest

Rabbit (150g), Car (200g), House (400g)

Step 4: Write the final order

Rabbit toy, Car toy, House toy

🐰 Rabbit (150g) < 🚗 Car (200g) < 🏠 House (400g)
Final answer:

Rabbit toy (150g), Car toy (200g), House toy (400g)

Applied rules:

• Ordering rule: Start with the smallest number and go to largest

• Comparison: Use < symbol to show increasing weight

• Arrangement: Lightest first, heaviest last

Rules and methods, laws,...
Weight A > Weight B → A is heavier
Weight Comparison Rule
Balance Scale Rule
Heavier side ↓
Heavier objects make the scale go down
Ordering Rule
Lightest → Heaviest
Smallest weight first, largest last
Estimation Rule
Compare to known objects
Use familiar items as reference points
Key definitions:

Weight: How heavy something is

Heavier: Having more weight than another object

Lighter: Having less weight than another object

Complete methodology:
  1. Identify weights: Look at the numbers given for each object
  2. Compare numbers: Use <, >, or = symbols
  3. Apply rules: Balance scale, ordering, or estimation
  4. State conclusion: Clearly say which is heavier/lighter
Tip 1: Remember: bigger number = heavier object when units are the same.
Tip 2: On a balance scale, the heavier side always goes down.
Tip 3: When ordering, start with the smallest weight number.
Tip 4: Estimate weight by comparing to familiar objects like toys or books.
Common errors: Forgetting to compare units, confusing heavier with lighter, misreading balance scales.
Exam preparation: Practice comparing numbers, learn balance scale rules, practice ordering objects by weight.
Formulas to know by heart:

• Heavier object has larger weight number

• Balance scale: heavier side goes down

• Ordering: smallest weight first

• Estimation: compare to known objects

Solution: Exercises 4 to 5
4 Estimating weight
Exercise 4
Estimate which object is heavier:
📚 Heavy textbook vs 📝 Thin notebook
Explain your reasoning.
Definition:

Estimation: Making a good guess about weight by comparing to known objects or using physical characteristics.

📚 Heavy textbook
Thicker pages
vs
📝 Thin notebook
Fewer pages
Step 1: Observe physical characteristics

The textbook has many thick pages, the notebook has few thin pages

Step 2: Compare to known objects

I know that thicker books are usually heavier than thin notebooks

Step 3: Make an educated guess

The textbook is likely heavier due to more pages and thickness

Step 4: Verify reasoning

More paper usually means more weight

📚 Heavy textbook is estimated to be heavier
Final answer:

The heavy textbook is heavier because it has more pages and is thicker than the thin notebook

Applied rules:

• Estimation: Compare physical characteristics

• Experience: Use knowledge of similar objects

• Reasoning: More material typically equals more weight

5 Adding weights
Exercise 5
If a 🧸 Teddy bear weighs 250g and a 🦆 Rubber duck weighs 50g,
what is the total weight when combined?
Which is heavier: the teddy alone or both together?
Definition:

Total weight: The sum of individual weights when objects are combined together.

🧸 Teddy
250g
+
🦆 Duck
50g
=
Combined
300g
Step 1: Identify individual weights

Teddy bear = 250g, Rubber duck = 50g

Step 2: Add the weights

250g + 50g = 300g

Step 3: Compare combined vs individual

300g (combined) vs 250g (teddy alone)

Step 4: State the comparison

300g > 250g, so the combination is heavier

Total weight = 300g. Combined is heavier than teddy alone.
Final answer:

Total weight is 300g. The combination (300g) is heavier than the teddy bear alone (250g).

Applied rules:

• Addition: Combine weights by adding numbers

• Comparison: 300g > 250g, so combined is heavier

• Total: Sum of parts is always greater than individual part

Key Concepts: Weight Comparison Techniques
Weight A > Weight B
Weight Comparison
Key definitions:

Weight: A measure of how heavy something is

Mass: The amount of matter in an object (often measured in grams)

Balance Scale: A tool that compares weights by showing which side is heavier

Complete methodology:
  1. Identify: Find the weight of each object
  2. Compare: Use mathematical symbols (> , < , =)
  3. Apply: Use specific rules for scales or ordering
  4. Verify: Check that your answer makes sense
Tip 1: When comparing weights, always ensure units are the same (grams, pounds, etc.).
Tip 2: On a balance scale, the side that goes down has the heavier object.
Tip 3: When ordering from lightest to heaviest, arrange from smallest to largest number.
Tip 4: Estimate weight by comparing to familiar objects like your pencil or book.
Common errors: Mixing up units, confusing heavier with lighter, forgetting that combined weights add up.
Real-world applications: Shopping (comparing package weights), cooking (measuring ingredients), packing (balancing luggage weight).
Essential rules:

• Heavier objects have larger weight numbers

• Balance scale: heavier side tilts down

• When combining objects, add their weights

• Estimation uses familiar objects as reference points

Questions & Answers

Question: I see a balance scale with a big ball on one side and a small cube on the other. The big ball side goes down. Isn't the small cube supposed to be lighter since it's smaller?

Answer: Great observation, Johnny! Size doesn't always determine weight. Here's what's happening:

  • Size vs. Weight: The big ball might be made of a heavy material (like metal) while the small cube could be made of a light material (like foam).
  • Balance Scale Rule: The side that goes down always has the heavier object, regardless of size.
  • Example: A large balloon is much bigger than a small rock, but the rock is heavier!

Always remember: On a balance scale, the downward side indicates the heavier object, not necessarily the bigger one.

Question: When I have to put objects in order from lightest to heaviest, how do I make sure I get the order right?

Answer: Here's a foolproof method for ordering objects by weight:

  • Step 1: Write down the weight of each object next to its picture or name
  • Step 2: Compare the numbers using the < symbol (less than)
  • Step 3: Start with the smallest number and work up to the largest
  • Step 4: Double-check by comparing each adjacent pair

Example: If you have 150g, 300g, and 200g, you'd order them as: 150g < 200g < 300g

This method ensures you never skip a weight or put them in the wrong sequence!

Question: I sometimes have to estimate weight without a scale. How can I get better at this?

Answer: Estimating weight improves with practice! Here are effective strategies:

  • Create mental references: Know that a typical apple weighs about 150g, a pencil is about 5g
  • Compare to known objects: "This book feels about as heavy as my math textbook"
  • Consider material and size: Metal objects are usually heavier than plastic ones of the same size
  • Practice lifting: Gently lift objects to feel their relative weights

Start by estimating the weight of common classroom objects, then check with actual measurements to refine your accuracy. Over time, you'll develop excellent weight estimation skills!