Lesson 13.2: Gross, Net, and Tare Weight Calculations

Applied concepts and practical problem solving for Gross, Net, and Tare Weight Calculations.

⏱️ Reading Time: 20 mins • ❓ 50 Interactive Practice Questions
🌟

Real-Life Story: Weight and Mass

Honey Apiary Farm: Weighing glass jars before and after filling with golden honey.

💡 Core Mathematical Concepts: Gross, Net, and Tare Weight Calculations

Focus areas: Net Weight = Gross Weight - Container Weight (Tare)..

Concept / Term Mathematical Meaning Real-Life Application
Gross Weight The total combined weight of the product PLUS its container/packaging Full jar on scale
Tare Weight The weight of the empty container or packaging alone Empty glass jar
Net Weight The actual weight of the contents/goods alone Net = Gross - Tare

📝 Step-by-Step Worked Examples

Worked Example 1: Calculate Net Weight

Full crate is 14.5 kg, empty crate is 1.8 kg -> Net fruit = 14.5 - 1.8 = 12.7 kg.

Worked Example 2: Calculate Gross Weight

500 g of cereal packed in 65 g box -> Gross = 500 + 65 = 565 g.

⚠️ Common Misconceptions to Avoid

Common Misconception: Confusing net and gross

Correction: Gross is ALWAYS the heaviest quantity because it includes packaging.

Common Misconception: Adding tare to gross

Correction: Tare must be subtracted from gross to find net weight.

🎯

Self-Check Challenge

A wooden crate packed with oranges has a gross mass of 18.4 kg. If the empty wooden crate weighs 2.6 kg, what is the net mass of the oranges?

Answer & Explanation:

Net mass = 18.4 kg - 2.6 kg = 15.8 kg.

🎯 Key Learning Takeaways

Extend understanding of Gross, Net, and Tare Weight Calculations. Solve multi-step real-world problems systematically. Verify solutions through mathematical reasoning.

📄 Printable Worksheets (5 Available)

Download ready-to-print PDFs for offline student practice with separate parent/teacher answer keys.

G5-M-CH13-WS05 A4 • 15 Qs

Weight and Mass: Worksheet 5

Practice Assessment 5 • Central Botanical Gardens Context

G5-M-CH13-WS04 A4 • 15 Qs

Weight and Mass: Worksheet 4

Practice Assessment 4 • Eco-Friendly Solar Park Context

G5-M-CH13-WS03 A4 • 15 Qs

Weight and Mass: Worksheet 3

Practice Assessment 3 • Harbor Marine Terminal Context

G5-M-CH13-WS02 A4 • 15 Qs

Weight and Mass: Worksheet 2

Practice Assessment 2 • Science & Discovery Museum Context

G5-M-CH13-WS01 A4 • 15 Qs

Weight and Mass: Worksheet 1

Practice Assessment 1 • City Regional Airport Context

✍️ Lesson Practice Questions (50 Questions)

Solve these real-world challenges online, test your understanding, and reveal instant step-by-step explanations.

Non-Repetitive Real-Life Maths
1 Short Answer
Hard 2 Marks
A warehouse elevator has a safe load limit of 1.2 metric tons (1,200 kg). If 15 workers averaging 72 kg each enter the elevator, how much additional cargo mass can safely be loaded?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 120 kg
Step-by-Step Explanation: Workers mass = 15 × 72 = 1,080 kg. Remaining capacity = 1,200 - 1,080 = 120 kg.
2 Short Answer
Hard 2 Marks
A balance scale has 3 identical mystery steel balls and a 200 g weight on the left pan, and a 1 kg weight and a 100 g weight on the right pan. If the scale balances evenly, what is the mass of one steel ball?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 300 g
Step-by-Step Explanation: Right pan = 1,100 g. Left pan = 3 balls + 200 g. 3 balls = 1,100 - 200 = 900 g. One ball = 900 ÷ 3 = 300 g.
3 Short Answer
Hard 2 Marks
Why is mass measured in kilograms and grams independent of gravity, unlike weight measured in newtons?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Mass is the fundamental quantity of matter inside an object, which stays the same whether on Earth, the Moon, or in deep space.
Step-by-Step Explanation: Mass is an invariant scalar quantity representing amount of matter.
4 Short Answer
Hard 2 Marks
Explain the difference between gross weight, tare weight, and net weight using an example of a jar of strawberry jam.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Gross weight is the total mass of jar plus jam. Tare weight is the empty glass jar alone. Net weight is the mass of the jam alone (Gross - Tare = Net).
Step-by-Step Explanation: Net weight represents the usable product mass excluding packaging tare.
5 Short Answer
Medium 1 Mark
A clerk calculates 5,040 g as 50 kg 40 g. Correct the clerk's conversion.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 5 kg 40 g
Step-by-Step Explanation: 5,000 g is 5 kg, not 50 kg. 5,040 g = 5 kg 40 g.
6 Short Answer
Medium 1 Mark
A student writes: '2 kg 5 g = 2,500 g.' Identify the error and state the correct mass in grams.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 2,005 g
Step-by-Step Explanation: The student confused 5 g with 500 g. 2 kg = 2,000 g, so 2,000 + 5 = 2,005 g.
7 Fill in the Blanks
Medium 1 Mark
Find the missing balance weight: [ ? ] g + 1,450 g = 3,000 g.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 1,550
Step-by-Step Explanation: 3,000 - 1,450 = 1,550 g.
8 Fill in the Blanks
Medium 1 Mark
Complete the mass conversion: 8 kg 75 g = [ ? ] grams.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 8,075
Step-by-Step Explanation: 8 × 1,000 + 75 = 8,075 grams.
9 Short Answer
Medium 1 Mark
A baker uses 650 g of flour for one loaf of artisan bread. How much flour (in kilograms and grams) is required to bake 6 loaves?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3 kg 900 g
Step-by-Step Explanation: 650 g × 6 = 3,900 g = 3 kg 900 g.
10 Short Answer
Medium 1 Mark
A shipping parcel has a gross weight of 4 kg 250 g. The cardboard packaging weighs 450 g. What is the net mass of the contents inside?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3 kg 800 g
Step-by-Step Explanation: 4,250 g - 450 g = 3,800 g = 3 kg 800 g.
11 Short Answer
Medium 1 Mark
At the Central Botanical Gardens, an animal shelter receives 3 bags of dog food weighing 15 kg each and 4 bags of cat food weighing 5 kg each. What is the total mass of pet food received?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 65 kg
Step-by-Step Explanation: (3 × 15 kg = 45 kg) + (4 × 5 kg = 20 kg) = 65 kg.
12 Multiple Choice
Easy 1 Mark
Which item is most realistically estimated to weigh approximately 1 kilogram?
A A 1-liter bag of sugar
B A postage stamp
C A standard school bus
D A paperclip
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: A 1-liter bag of sugar
Step-by-Step Explanation: A standard bag of flour or sugar weighs about 1 kilogram.
13 Multiple Choice
Easy 1 Mark
What is 3.75 kg expressed in grams?
A 3,750 g
B 375 g
C 37,500 g
D 3,075 g
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3,750 g
Step-by-Step Explanation: 3.75 × 1,000 = 3,750 g.
14 Multiple Choice
Easy 1 Mark
How many kilograms and grams are in 6,450 grams?
A 6 kg 450 g
B 64 kg 50 g
C 6 kg 45 g
D 645 kg
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 6 kg 450 g
Step-by-Step Explanation: 6,450 g = 6,000 g + 450 g = 6 kg 450 g.
15 Multiple Choice
Easy 1 Mark
Convert 20 kilograms into grams.
A 20,000 g
B 2,000 g
C 200,000 g
D 2,000 g
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 20,000 g
Step-by-Step Explanation: 1 kg = 1,000 g. 20 × 1,000 = 20,000 grams.
16 Short Answer
Hard 2 Marks
A warehouse elevator has a safe load limit of 1.2 metric tons (1,200 kg). If 15 workers averaging 72 kg each enter the elevator, how much additional cargo mass can safely be loaded?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 120 kg
Step-by-Step Explanation: Workers mass = 15 × 72 = 1,080 kg. Remaining capacity = 1,200 - 1,080 = 120 kg.
17 Short Answer
Hard 2 Marks
A balance scale has 3 identical mystery steel balls and a 200 g weight on the left pan, and a 1 kg weight and a 100 g weight on the right pan. If the scale balances evenly, what is the mass of one steel ball?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 300 g
Step-by-Step Explanation: Right pan = 1,100 g. Left pan = 3 balls + 200 g. 3 balls = 1,100 - 200 = 900 g. One ball = 900 ÷ 3 = 300 g.
18 Short Answer
Hard 2 Marks
Why is mass measured in kilograms and grams independent of gravity, unlike weight measured in newtons?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Mass is the fundamental quantity of matter inside an object, which stays the same whether on Earth, the Moon, or in deep space.
Step-by-Step Explanation: Mass is an invariant scalar quantity representing amount of matter.
19 Short Answer
Hard 2 Marks
Explain the difference between gross weight, tare weight, and net weight using an example of a jar of strawberry jam.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Gross weight is the total mass of jar plus jam. Tare weight is the empty glass jar alone. Net weight is the mass of the jam alone (Gross - Tare = Net).
Step-by-Step Explanation: Net weight represents the usable product mass excluding packaging tare.
20 Short Answer
Medium 1 Mark
A clerk calculates 5,040 g as 50 kg 40 g. Correct the clerk's conversion.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 5 kg 40 g
Step-by-Step Explanation: 5,000 g is 5 kg, not 50 kg. 5,040 g = 5 kg 40 g.
21 Short Answer
Medium 1 Mark
A student writes: '2 kg 5 g = 2,500 g.' Identify the error and state the correct mass in grams.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 2,005 g
Step-by-Step Explanation: The student confused 5 g with 500 g. 2 kg = 2,000 g, so 2,000 + 5 = 2,005 g.
22 Fill in the Blanks
Medium 1 Mark
Find the missing balance weight: [ ? ] g + 1,450 g = 3,000 g.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 1,550
Step-by-Step Explanation: 3,000 - 1,450 = 1,550 g.
23 Fill in the Blanks
Medium 1 Mark
Complete the mass conversion: 8 kg 75 g = [ ? ] grams.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 8,075
Step-by-Step Explanation: 8 × 1,000 + 75 = 8,075 grams.
24 Short Answer
Medium 1 Mark
A baker uses 650 g of flour for one loaf of artisan bread. How much flour (in kilograms and grams) is required to bake 6 loaves?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3 kg 900 g
Step-by-Step Explanation: 650 g × 6 = 3,900 g = 3 kg 900 g.
25 Short Answer
Medium 1 Mark
A shipping parcel has a gross weight of 4 kg 250 g. The cardboard packaging weighs 450 g. What is the net mass of the contents inside?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3 kg 800 g
Step-by-Step Explanation: 4,250 g - 450 g = 3,800 g = 3 kg 800 g.
26 Short Answer
Medium 1 Mark
At the Eco-Friendly Solar Park, an animal shelter receives 3 bags of dog food weighing 15 kg each and 4 bags of cat food weighing 5 kg each. What is the total mass of pet food received?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 65 kg
Step-by-Step Explanation: (3 × 15 kg = 45 kg) + (4 × 5 kg = 20 kg) = 65 kg.
27 Multiple Choice
Easy 1 Mark
Which item is most realistically estimated to weigh approximately 1 kilogram?
A A 1-liter bag of sugar
B A postage stamp
C A standard school bus
D A paperclip
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: A 1-liter bag of sugar
Step-by-Step Explanation: A standard bag of flour or sugar weighs about 1 kilogram.
28 Multiple Choice
Easy 1 Mark
What is 3.75 kg expressed in grams?
A 3,750 g
B 375 g
C 37,500 g
D 3,075 g
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3,750 g
Step-by-Step Explanation: 3.75 × 1,000 = 3,750 g.
29 Multiple Choice
Easy 1 Mark
How many kilograms and grams are in 6,450 grams?
A 6 kg 450 g
B 64 kg 50 g
C 6 kg 45 g
D 645 kg
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 6 kg 450 g
Step-by-Step Explanation: 6,450 g = 6,000 g + 450 g = 6 kg 450 g.
30 Multiple Choice
Easy 1 Mark
Convert 16 kilograms into grams.
A 16,000 g
B 1,600 g
C 160,000 g
D 1,600 g
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 16,000 g
Step-by-Step Explanation: 1 kg = 1,000 g. 16 × 1,000 = 16,000 grams.
31 Short Answer
Hard 2 Marks
A warehouse elevator has a safe load limit of 1.2 metric tons (1,200 kg). If 15 workers averaging 72 kg each enter the elevator, how much additional cargo mass can safely be loaded?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 120 kg
Step-by-Step Explanation: Workers mass = 15 × 72 = 1,080 kg. Remaining capacity = 1,200 - 1,080 = 120 kg.
32 Short Answer
Hard 2 Marks
A balance scale has 3 identical mystery steel balls and a 200 g weight on the left pan, and a 1 kg weight and a 100 g weight on the right pan. If the scale balances evenly, what is the mass of one steel ball?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 300 g
Step-by-Step Explanation: Right pan = 1,100 g. Left pan = 3 balls + 200 g. 3 balls = 1,100 - 200 = 900 g. One ball = 900 ÷ 3 = 300 g.
33 Short Answer
Hard 2 Marks
Why is mass measured in kilograms and grams independent of gravity, unlike weight measured in newtons?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Mass is the fundamental quantity of matter inside an object, which stays the same whether on Earth, the Moon, or in deep space.
Step-by-Step Explanation: Mass is an invariant scalar quantity representing amount of matter.
34 Short Answer
Hard 2 Marks
Explain the difference between gross weight, tare weight, and net weight using an example of a jar of strawberry jam.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Gross weight is the total mass of jar plus jam. Tare weight is the empty glass jar alone. Net weight is the mass of the jam alone (Gross - Tare = Net).
Step-by-Step Explanation: Net weight represents the usable product mass excluding packaging tare.
35 Short Answer
Medium 1 Mark
A clerk calculates 5,040 g as 50 kg 40 g. Correct the clerk's conversion.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 5 kg 40 g
Step-by-Step Explanation: 5,000 g is 5 kg, not 50 kg. 5,040 g = 5 kg 40 g.
36 Short Answer
Medium 1 Mark
A student writes: '2 kg 5 g = 2,500 g.' Identify the error and state the correct mass in grams.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 2,005 g
Step-by-Step Explanation: The student confused 5 g with 500 g. 2 kg = 2,000 g, so 2,000 + 5 = 2,005 g.
37 Fill in the Blanks
Medium 1 Mark
Find the missing balance weight: [ ? ] g + 1,450 g = 3,000 g.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 1,550
Step-by-Step Explanation: 3,000 - 1,450 = 1,550 g.
38 Fill in the Blanks
Medium 1 Mark
Complete the mass conversion: 8 kg 75 g = [ ? ] grams.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 8,075
Step-by-Step Explanation: 8 × 1,000 + 75 = 8,075 grams.
39 Short Answer
Medium 1 Mark
A baker uses 650 g of flour for one loaf of artisan bread. How much flour (in kilograms and grams) is required to bake 6 loaves?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3 kg 900 g
Step-by-Step Explanation: 650 g × 6 = 3,900 g = 3 kg 900 g.
40 Short Answer
Medium 1 Mark
A shipping parcel has a gross weight of 4 kg 250 g. The cardboard packaging weighs 450 g. What is the net mass of the contents inside?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3 kg 800 g
Step-by-Step Explanation: 4,250 g - 450 g = 3,800 g = 3 kg 800 g.
41 Short Answer
Medium 1 Mark
At the Harbor Marine Terminal, an animal shelter receives 3 bags of dog food weighing 15 kg each and 4 bags of cat food weighing 5 kg each. What is the total mass of pet food received?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 65 kg
Step-by-Step Explanation: (3 × 15 kg = 45 kg) + (4 × 5 kg = 20 kg) = 65 kg.
42 Multiple Choice
Easy 1 Mark
Which item is most realistically estimated to weigh approximately 1 kilogram?
A A 1-liter bag of sugar
B A postage stamp
C A standard school bus
D A paperclip
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: A 1-liter bag of sugar
Step-by-Step Explanation: A standard bag of flour or sugar weighs about 1 kilogram.
43 Multiple Choice
Easy 1 Mark
What is 3.75 kg expressed in grams?
A 3,750 g
B 375 g
C 37,500 g
D 3,075 g
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 3,750 g
Step-by-Step Explanation: 3.75 × 1,000 = 3,750 g.
44 Multiple Choice
Easy 1 Mark
How many kilograms and grams are in 6,450 grams?
A 6 kg 450 g
B 64 kg 50 g
C 6 kg 45 g
D 645 kg
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 6 kg 450 g
Step-by-Step Explanation: 6,450 g = 6,000 g + 450 g = 6 kg 450 g.
45 Multiple Choice
Easy 1 Mark
Convert 12 kilograms into grams.
A 12,000 g
B 1,200 g
C 120,000 g
D 1,200 g
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 12,000 g
Step-by-Step Explanation: 1 kg = 1,000 g. 12 × 1,000 = 12,000 grams.
46 Short Answer
Hard 2 Marks
A warehouse elevator has a safe load limit of 1.2 metric tons (1,200 kg). If 15 workers averaging 72 kg each enter the elevator, how much additional cargo mass can safely be loaded?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 120 kg
Step-by-Step Explanation: Workers mass = 15 × 72 = 1,080 kg. Remaining capacity = 1,200 - 1,080 = 120 kg.
47 Short Answer
Hard 2 Marks
A balance scale has 3 identical mystery steel balls and a 200 g weight on the left pan, and a 1 kg weight and a 100 g weight on the right pan. If the scale balances evenly, what is the mass of one steel ball?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 300 g
Step-by-Step Explanation: Right pan = 1,100 g. Left pan = 3 balls + 200 g. 3 balls = 1,100 - 200 = 900 g. One ball = 900 ÷ 3 = 300 g.
48 Short Answer
Hard 2 Marks
Why is mass measured in kilograms and grams independent of gravity, unlike weight measured in newtons?
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Mass is the fundamental quantity of matter inside an object, which stays the same whether on Earth, the Moon, or in deep space.
Step-by-Step Explanation: Mass is an invariant scalar quantity representing amount of matter.
49 Short Answer
Hard 2 Marks
Explain the difference between gross weight, tare weight, and net weight using an example of a jar of strawberry jam.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: Gross weight is the total mass of jar plus jam. Tare weight is the empty glass jar alone. Net weight is the mass of the jam alone (Gross - Tare = Net).
Step-by-Step Explanation: Net weight represents the usable product mass excluding packaging tare.
50 Short Answer
Medium 1 Mark
A clerk calculates 5,040 g as 50 kg 40 g. Correct the clerk's conversion.
💡 Click to View Correct Answer & Explanation ▼
Correct Answer: 5 kg 40 g
Step-by-Step Explanation: 5,000 g is 5 kg, not 50 kg. 5,040 g = 5 kg 40 g.
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