Introduction
In PSLE Science, students must know practical ways to measure volume/capacity of irregular containers that don’t have markings. A coin bank is a perfect example. The fastest approach is the fill-and-pour method using a measuring cylinder. This question also checks observation: can you spot the coin slot, which identifies the coin bank?
The Question
(a) Circle the coin bank.
(b) Describe one way to find the volume of the air space inside the coin bank.
Step-by-Step Explanation
Part (a): Identify the coin bank
Choose the picture with a slot/slit on the top where coins go in.
Part (b): Measure the volume inside (fill-and-pour)
- Seal the slot (e.g., tape or finger over the slit to prevent leaking).
- Fill the coin bank with water to the brim (no air gaps).
- Pour all the water into a measuring cylinder carefully.
- Read the meniscus at eye level and record the volume in mL (or cm³).
- State that capacity/volume of the coin bank = reading on the measuring cylinder.
- Reminder: 1 mL = 1 cm³ (either unit is acceptable).
Alternative acceptable method: Submerge a sealed coin bank in a displacement can or overflowing beaker and collect the overflowed water into a measuring cylinder; the collected volume equals the capacity.
Quick Concept Guide
| Concept | What to remember | Why it matters |
| Capacity vs Volume | Capacity = how much liquid a container can hold | The question asks for the inside volume |
| Measuring cylinder | Read bottom of meniscus at eye level | Prevents parallax error |
| Units | mL and cm³ are equivalent (1 mL = 1 cm³) | Use correct units |
| Sealing the slot | Prevents leaks while filling/pouring | Ensures accurate reading |
| Displacement idea | Liquid displaced = volume of space taken | Works for irregular shapes/containers |
Tips for Students
- Always state equipment (measuring cylinder) and key actions (fill to brim, pour, read meniscus).
- Mention units in your final answer.
- If the container has a hole/slot, remember to seal it first.
For Parents
This practical skill appears in many hands-on questions. We train students to write short, complete procedures that examiners can tick easily (equipment + steps + unit).