Skip to content
MeerkatSkool Afrikaans
Summaries · Grade 7 Natural Sciences › Scientific investigation and variables
Free summary · Grade 7 Natural Sciences

Scientific investigation and variables

Variables, hypotheses, control groups and how to do a fair investigation. Read one part at a time and tap “I know this”. Then test yourself in the quiz.

Know it already? Jump straight to the quiz

Your progress0 of 3

The process

InvestigativequestionHypothesisMethod(fair)Results in atableConclusion
Every good investigation follows these steps.

Frame the question like this: how does one variable affect another? For example: “Does soil type affect how tall bean plants grow?” Write a method that someone else could repeat, and record results in a table while you measure.

Variables: only one thing changes.
Variables: only one thing changes.
Tap when you could tell someone without looking.

A fair test

VariableBean example
Independent (change)The type of soil
Dependent (measure)The height of the plants
Controlled (same)Water, light, kind of seed
  • Plant more than one bean in each soil: one plant might be weak by chance.
  • If the two groups stand in different windows, it is not fair: the light is then not the same.
  • A line graph shows best how a plant grows week by week.
Tap when you could tell someone without looking.

Honest and safe

  • Do the results disprove your hypothesis? Report it honestly.
  • Wear safety goggles in the lab.
  • A chemical splashes on your skin: first rinse it with lots of water.
Tap when you could tell someone without looking.

Remember this and test yourself

Remember this: your summary
  • A hypothesis is a prediction that can be tested.
  • Independent variable: what you change. Dependent: what you measure. Controlled: what you keep the same.
  • The control group gets no treatment.
  • Repeat to see whether the result is reliable; use the same measuring tool for every reading.
  • An observation is what you see; a conclusion is what it means.

Write these points in your book. Read them again the night before the test.

Memory trick

Independent = I change it. Dependent = Data I measure (it depends on the first). Controlled = keep still.

Flash cards · Tap to turn over

Important words

First say what the word means, then turn the card over.

Test yourself · Part 2

True or false?

Read the question and the answer. Is the answer right? Tap True or False.

    Now the real quiz!

    The quiz has many more questions on this topic. Every question shows straight away whether you are right and explains why.

    Take the quiz: Scientific investigation and variables
    All Grade 7 Natural Sciences summaries
    For parents
    • Read one part together and ask your child to tell it back in their own words.
    • The ticks (“I know this”) are saved on this device only. We never ask for names or emails.

    Follows CAPS for Grade 7 Natural Sciences. Always check your teacher’s notes and textbook too.

    Free PDF