Lesson 13.1: Metric Mass Conversion and Scales
Comprehensive lesson on Metric Mass Conversion and Scales in Grade 5 Mathematics.
⏱️ Reading Time: 20 mins
• ❓ 50 Interactive Practice Questions
🌟
Real-Life Story: Weight and Mass
Produce Distribution Market: Weighing bulk sacks of sweet potatoes and gourmet mushrooms.
💡 Core Mathematical Concepts: Metric Mass Conversion and Scales
Focus areas: 1 kilogram (kg) = 1,000 grams (g); Reading analog and digital balance scales..
| Concept / Term | Mathematical Meaning | Real-Life Application |
|---|---|---|
| Gram (g) | Used for measuring light items like letters, spices, and stationery | A paperclip weighs ~1 g |
| Kilogram (kg) | Used for heavier objects like groceries, pets, and human weight | 1 kg = 1,000 g |
| Scale Increments | The value of each tick mark on an analog dial | If 0 to 1 kg has 10 divisions, each tick is 100 g |
📝 Step-by-Step Worked Examples
Worked Example 1: Convert 3.75 kg to grams
3.75 × 1,000 = 3,750 g.
Worked Example 2: Convert 850 g to kilograms
850 ÷ 1,000 = 0.85 kg.
⚠️ Common Misconceptions to Avoid
Common Misconception: Thinking 1 kg = 100 g
Correction: Always remember kilo means 1,000: 1 kg = 1,000 g.
Common Misconception: Misreading unlabelled scale divisions
Correction: Count total markings between major numbers before reading the needle.
🎯
Self-Check Challenge
A baker uses 750 g of white flour and 450 g of rye flour. What is the total weight of flour used in kilograms?
Answer & Explanation:
750 g + 450 g = 1,200 g. 1,200 ÷ 1,000 = 1.2 kg.
🎯 Key Learning Takeaways
Master core definitions of Metric Mass Conversion and Scales.
Apply mathematical principles to everyday scenarios.
Avoid common calculation and conceptual pitfalls.
📄 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.
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.