Tackling Control Set Up Questions Like a Pro (Primary Science Guide for Singapore)

“Why does my child seem to understand Science in class… but still lose marks in school examinations?”

Many parents in Singapore notice this especially from Primary 4 onwards, when Science questions become less about memorising facts and more about applying concepts. Some children adapt early and start scoring consistently because they understand how experiments work. Others fall behind — not because they are weaker, but because they never truly understood key terms like control setup, independent variable, and the aim of the experiment.

The truth is, many parents are already thinking ahead and quietly searching for ways to help their child avoid common PSLE Science pitfalls. One of the biggest turning points is learning the control setup meaning properly — and more importantly, learning how to apply it in exam-style questions.

At AGrader, we’ve helped 30,000+ students build strong foundations in Primary Science by teaching them how to interpret tricky experimental questions clearly, step-by-step.

By the end of this article, you’ll know exactly what a control setup is, why it matters, and how your child can answer control set questions confidently in exams.

What Experimental Questions in Primary School Are Really Testing

In Primary School Science, experimental questions test whether students can:

• Identify variables accurately

• Understand the aim of the experiment

• Explain cause-and-effect clearly

• Compare results properly between set-ups

This is why control setup questions appear so often in school examinations and PSLE Science practice papers.

Key Science Terms Students Must Know Before Control Set Questions

Before we dive into what is a control setup, your child must understand the most common terms used in experimental questions.

Variables 

In most PSLE Science experiments, there are three key variables:

1) Independent Variable (Changed Variable)

• This is the variable that is changed on purpose

• It is also called the independent variable

2) Constant Variables

• These are kept the same across all set-ups

• They ensure the experiment is fair

3) Measured Variable (Dependent Variable)

• This is what you measure or observe

• It is also called the dependent variable

Aim 

The aim of the experiment tells you:

How the independent variable affects the measured variable (dependent variable)

A simple format students can use is:

• To find out how ______ affects ______.

This helps students answer experimental questions clearly in school examinations.

Fair Test

In a fair test, only one variable is changed. Other variables are kept constant.

What Is a Control Setup? (Control Setup Meaning Explained Simply)

A control set-up is a set-up without the changed variable. The purpose of a control set-up is to prove that any changes in the results (the measured variable) are caused only by the changed variable, and not by any other factors.

Let’s explore how to approach and answer each type of question.

The 2 Most Common Control Setup Question Types in PSLE Science

In PSLE Science and Primary School exam papers, control set questions usually come in two formats:

1) Designing a control setup

Students must create a contol setup for an experiment.

2) Explaining the purpose of a control

Students must explain the purpose of a control setup.

Let’s go through both using a common exam-style scenario.

Example: Fish and Water Plants Experiment

From the example above, we have to design a control set-up! 

For this question, 

Aim: To study the effect of carbon dioxide given out by fish on the growth of water plants 

Changed Variable: Number of fishes, which determines the amount of carbon dioxide given out

Constant Variables: Number of water plants, Location of fish bowls (next to window), Volume of water in fish bowl

The control set-up will require the removal of the changed variable, and keep the other variables the same! 

Hence, the control set-up should use an identical fish bowl with the same volume of water and the same number of water plants, placed in the same location, but without any fish inside it.

Now let's look at the same example, but with a different question type.

From this example, what do you think is the purpose of Set-up C?

Set-up C has the same volume of water, the same number of plants, and is placed in the same location as Set-ups A and B, but it has no fish. This means that it does not have the changed variable.

Without the changed variable, it acts as a control set-up to ensure that the measured variable is affected only by the changed variable and not by any other factors.

Hence, Set-up C acts as a control set-up to ensure that the growth of the water plants is affected only by the amount of carbon dioxide given out by the fish, and not by other factors.

Why Control Setup Questions Matter in PSLE Science

Control setup questions are common in PSLE Science because they test true understanding of experiments.

Students who understand control setup meaning will:

• Identify variables faster

• Write clearer explanations

• Avoid vague answers

• Score better in experimental questions

Students who do not understand it often:

• Identify the wrong independent variable

• Remove the wrong variable

• Lose marks even when the experiment looks simple

That’s why learning how to tackle control set questions early in Primary School is a big advantage.

How AGrader Helps Students Improve in Primary School Science

At AGrader Learning Centre, we don’t just teach Science content — we train students to answer experimental questions in the way examiners expect.

Alongside regular weekly lessons aligned to the latest MOE syllabus, every student receives EverLoop, AGrader’s free after-class learning support included with every weekly lesson.

This helps students reinforce concepts through:

• Extra structured revision resources

• Exam-style practice questions

• Step-by-step explanation of common question patterns

• Continued support at no additional or hidden cost

Our experienced educators also focus on experimental skills that frequently appear in PSLE Science and school examinations, such as:

• Variables

• Independent variable vs dependent variable

• Aim of the experiment

• Control setup and fair testing

• Explaining results logically

Conclusion

Control setup questions may seem tricky at first, but once students understand the logic, they become one of the easiest scoring areas in PSLE Science. When your child knows the control setup meaning and how to apply it, they stop guessing and start answering confidently.

The bigger risk is not that students cannot learn this — it’s that they learn it too late. If a child keeps losing marks in experimental questions year after year, they may start believing they are “not good at Science”, when the real issue is simply missing technique and practice.

This is where the right guidance matters. At AGrader Learning Centre Primary Science Programme, we teach students how to identify the change variable (independent variable), write the aim of the experiment correctly, and explain results clearly so the measured variable is affected only by the changed variable.

With EverLoop, our free after-class revision support included with every weekly lesson, students receive consistent reinforcement and practice at no extra cost — helping them build confidence steadily instead of cramming at the last minute.

We encourage you to enrol your child early, as our best time slots are filling up quickly. Secure a place now to ensure your child benefits from structured weekly lessons and complimentary EverLoop support.

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