Measurement Notes, Quizzes & Revision
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Subtopic: Measurement (for age_replace learners, Kenya)
What is measurement?
Measurement is the way we find out how long, heavy, full or long-lasting something is. In Kenya we use the metric system for official measurements (metres, litres, kilograms and seconds). These notes introduce key ideas, names of tools, units and simple calculations useful for age_replace learners.
Basic measuring quantities and common units
- Length / distance: metre (m), centimetre (cm), millimetre (mm), kilometre (km). Example in Kenya: road signs show km; a classroom might be about 6โ8 m wide.
- Mass (weight): kilogram (kg), gram (g). Example: a bag of maize may be 2 kg, a jikos charcoal bag around 10 kg.
- Capacity (volume): litre (L), millilitre (mL). Example: a jerrycan often holds 20 L; a soft drink bottle 500 mL.
- Time: second (s), minute (min), hour (h). Example: school bell rings every hour for lessons or breaks.
- Area & Perimeter (basic): square metre (mยฒ) for area; perimeter is measured in metres (m).
Common measuring tools
- Ruler (30 cm): measures length in cm and mm.
- Measuring tape: measures longer lengths (metres and cm).
- Weighing scale (digital or balance): measures mass (g, kg).
- Measuring jug or jerrycan: measures volume in litres.
- Stopwatch or clock: measures time in s, min, h.
Simple visual: a 30 cm ruler (not to scale)
|0cm|---1cm---|---2cm---|---3cm---|---4cm---|---5cm---|...|30cm|
Long marks = centimetres; small marks between = millimetres (10 mm = 1 cm).
Units conversion (easy rules)
- Length: 1 m = 100 cm; 1 cm = 10 mm; 1 km = 1000 m.
- Mass: 1 kg = 1000 g.
- Volume: 1 L = 1000 mL.
- Time: 1 h = 60 min; 1 min = 60 s.
Tip: To change m to cm, multiply by 100. To change cm to m, divide by 100.
Worked examples with Kenya context
Example 1 โ Length:
A football pitch in a nearby school is 90 m long. How many centimetres long is it?
Solution: 90 m ร 100 = 9000 cm.
Example 2 โ Mass:
A farmer has bags of maize each 10 kg. How many grams in one bag?
Solution: 10 kg ร 1000 = 10 000 g.
Example 3 โ Capacity:
A jerrycan holds 20 L. How many 500 mL bottles can be filled from one jerrycan?
Solution: 20 L = 20 000 mL. 20 000 รท 500 = 40 bottles.
Example 4 โ Time:
If a lesson lasts 40 minutes, how many seconds is that?
Solution: 40 ร 60 = 2400 seconds.
Perimeter and area (simple)
Perimeter = distance around a shape (measured in metres). Area = space inside a shape (measured in mยฒ).
Square or rectangle:
Perimeter of rectangle = 2 ร (length + width).
Area of rectangle = length ร width.
Area of rectangle = length ร width.
Example: a classroom is 8 m long and 6 m wide.
Perimeter = 2 ร (8 + 6) = 28 m. Area = 8 ร 6 = 48 mยฒ.
Perimeter = 2 ร (8 + 6) = 28 m. Area = 8 ร 6 = 48 mยฒ.
Short practical activities (class or home)
- Measure your classroom: use a tape to find length and width, then calculate area in mยฒ.
- Weigh fruit or vegetables at home (use kitchen scale) and record masses in grams and kilograms.
- Compare volumes: pour water from a 2 L bottle into 250 mL cups โ how many cups fill it?
- Time a short run: use a stopwatch and record time in seconds and minutes.
Practice questions
- Convert 3.5 m to centimetres.
- A maize sack is 25 kg. How many grams is this?
- If a water tank holds 150 L, how many 5 L buckets are needed to empty it?
- Find the perimeter and area of a playground 30 m by 20 m.
- How many minutes are in 3 hours?
Answers:
1) 350 cm 2) 25 000 g 3) 30 buckets 4) Perimeter 100 m, Area 600 mยฒ 5) 180 minutes
Key vocabulary (Kenyan classroom focus)
- Measure, metre, centimetre, millimetre, kilometre
- Kilogram, gram, weigh, scales
- Litres, millilitres, capacity, jerrycan
- Time, seconds, minutes, hours, stopwatch
- Perimeter, area