Science notes, unit 1

Scientific skills

Textbook Science Year 5 (DLP), pages 1–18

What this chapter covers

You can use the twelve science process skills to find out about things (1.1.1 to 1.1.12)
You can tell the difference between an observation, an inference and a prediction (1.1.1, 1.1.4, 1.1.5)
You can read tables, charts and graphs and use them to communicate and interpret data (1.1.6, 1.1.8)
You can identify the manipulated, responding and constant variables in an investigation (1.1.10)
You can write a hypothesis and an operational definition (1.1.9, 1.1.11)
You can describe the steps of a fair test and write a conclusion (1.1.12)

In Year 5 you use twelve science process skills to solve problems. Six are the skills you learned in Year 3. The other six are: using space-time relationship, interpreting data, defining operationally, controlling variables, making a hypothesis and experimenting. Together they let you plan and carry out a fair test.

Four children playing tarik upih in a yard; one pulls a friend sitting on a palm sheath — Playing tarik upih. A heavy load is hard to pull fast: the pupils **observe**, **infer** and **predict** without even knowing it.

1.1Science process skills

The first six skills

Skill	What it means	Example from the paper plane competition
Observing	Using the senses to collect information	The nose cone of Ana's plane is long and pointed.
Classifying	Sorting things into groups by a characteristic	Planes sorted by the size of their wings.
Measuring and using numbers	Using tools and standard units	The plane travelled 450 cm (a sample result, measured with a measuring tape).
Making inferences	Giving a sensible reason for an observation	Maybe the plane flew far because its wings are large.
Predicting	Saying what will happen next, using evidence or a pattern	"I predict your plane will fly far because of its large wings."
Communicating	Sharing information in a table, chart, graph, drawing or words	A table of the distance for each stretch.

An observation is what you sense. An inference is the reason you give. A prediction is what will happen next. "The floor is wet" is an observation. "Maybe someone spilled water" is an inference. "Someone may slip" is a prediction.

Skills in the Mind Test

Classifying by use: the pencil, hole puncher and stapler are stationery; the oven mitt, wooden ladle and kettle are kitchen utensils.
Inferring. Observation: large logs float on water. Inference: they are less dense than water. Observation: the rate of breathing is higher after exercise. Inference: the body needs more oxygen.
Predicting: Pupil A rides a motorcycle and Pupil B cycles, over the same 1 km. Prediction: Pupil A will take a shorter time than Pupil B.
Litmus paper: an alkali turns red litmus paper blue. A substance that turns blue litmus paper red is an acid. A substance that changes neither paper is neutral.

Ten numbered pictures showing how to fold a paper plane — Ana's folding steps. Following steps in the right order is also a skill.

Using space-time relationship

Using space-time relationship means describing how something changes as time passes: its position, size, shape, direction or amount.

Example: a seedling grows taller and taller as the days pass, so its height changes with time. A bubble that is bigger takes a longer time to burst.

Writing a space-time statement

Two pictures of a plant, two days apart. The plant is 4 cm tall, then 7 cm tall.
"The height of the plant increases from 4 cm to 7 cm after 2 days."

Interpreting data

Interpreting data means explaining what the numbers in a table, chart or graph tell us: the patterns, the highest and lowest values, and the reason for them.

Look at the glycerine results. The more glycerine there is, the longer the time.

Quantity of glycerine (tablespoons)	Time for the bubble to burst (s)
1	45
3	120
5	145

Line graph: 1 tablespoon 45 seconds, 3 tablespoons 120 seconds, 5 tablespoons 145 seconds — The same data as a graph. The line goes up: more glycerine, a longer time.

To interpret a graph, ask three questions. What is the highest? What is the lowest? What pattern do you see as the numbers change? Then write one sentence for the pattern.

Use the table: how much longer does the bubble last with 5 tablespoons than with 1 tablespoon?

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145 − 45 = 100 seconds longer.

Variables and controlling variables

A variable is something that can change in an investigation. There are three kinds.

Variable	Meaning	Paper plane investigation
Manipulated (changed)	The one thing you change on purpose	Length of the stretched rubber band (10, 20, 30 cm)
Responding (measured)	What changes because of it; you measure it	Distance travelled by the paper plane
Constant (fixed)	Everything else, kept the same	Type, size and thickness of the paper; the folding design

Controlling variables means changing only the manipulated variable and keeping the constant variables the same. This makes it a fair test.

Mr Zaki gave every pupil the same type of paper, so the size and thickness were the same too. The type, size and thickness of the paper are constant variables that make the test fair.

Change only one thing at a time. If you change the wing size and the paper thickness together, you cannot tell which one made the difference.

In the glycerine experiment, name the manipulated and the responding variables.

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Manipulated: quantity of glycerine. Responding: time taken for the soap bubble to burst. Constant (any): type of dishwashing liquid, volume of water, size of the bubbles, speed of the wind.

Making a hypothesis

A hypothesis is a statement that suggests the relationship between the manipulated variable and the responding variable. It can be tested.

Model: The more (or less, longer, higher) the manipulated variable, the more (or less, longer, higher) the responding variable.

Example

"The greater the quantity of glycerine used, the longer the time taken for the soap bubbles to burst."

A hypothesis is not a question (that is the problem statement) and it is not the aim. The aim begins with "To investigate...". The problem statement begins "Does...?".

Defining operationally

Defining operationally means saying what something is by what you do and what you observe or measure in the investigation.

Thing to define	Operational definition
Durability of the soap bubbles	The time taken for the soap bubbles to burst.
Distance travelled by the paper plane	The length from the starting point to where the plane lands, measured with a measuring tape.
An alkali	A substance that turns red litmus paper blue.

A dictionary definition says what a thing is. An operational definition says what you do and what you measure or observe. It often starts with "The time taken...", "The length from..." or "...changes the colour of...".

Experimenting

Experimenting means carrying out a fair test to check a hypothesis, by following a plan and recording the results.

Use these steps in order, as Ana and her friends did for the soap bubbles.

Aim: "To investigate the relationship between the quantity of glycerine and the time taken for the soap bubbles to burst."
Problem statement: "Does a different quantity of glycerine affect the time taken for the soap bubbles to burst?"
Hypothesis: the more glycerine, the longer the time.
Variables: manipulated, responding, constant.
Apparatus and materials: safety goggles, measuring cylinder, stopwatch, plastic container with a lid, drinking straw, tablespoon, water, dishwashing liquid, glycerine.
Steps: a clear list in order, repeated for each value of the manipulated variable.
Data: a table of results.
Analysing the data: say what the table shows.
Conclusion: say if the hypothesis is accepted or not accepted.

Four children making giant soap bubbles in a park, with buckets of soap solution — The problem: how can we make bubbles that do not burst quickly?

Soap solution being prepared in a plastic container; one tablespoon of glycerine being added — Making the soap solution: 200 mL water and 50 mL dishwashing liquid, then 1 tablespoon of glycerine, stirred without making bubbles. The solution is left for four hours at room temperature before use.

Wear safety goggles and work in a place with little wind. Wind is a constant variable, and goggles protect your eyes from soap.

The result was 45 s for 1 tablespoon, 120 s for 3 tablespoons and 145 s for 5 tablespoons. The conclusion: the hypothesis is accepted. The higher the quantity of glycerine, the longer the time taken for the soap bubble to burst.

1.2Science process skills in solving problems

Scientists do not use the skills one by one. They use many together. Look at the paper plane investigation.

Three photos: rubber band fastened to a paper clip and pencil, a pupil stretching the band 10 cm, then releasing the plane — Steps 4 to 6 of the paper plane launch test.

Two pupils measuring the distance of a paper plane on the floor with a measuring tape — Measure the distance travelled by the plane.

Step	Skill used
Look at the plane in flight	Observing
Say why it flew farther	Making inferences
Stretch the rubber band 10, 20 and 30 cm	Controlling variables (manipulated)
Measure the distance with a tape	Measuring and using numbers
Record in a table or chart	Communicating
State that the farther the stretch, the farther the plane flies	Making a hypothesis / interpreting data

The investigation in short

Aim: to investigate the relationship between the length of the stretched rubber band and the distance travelled by the plane.
Manipulated: length of stretched rubber band. Responding: distance travelled by the plane. Constant: the same plane, the same paper clip, the same pupil launching.
Relationship: the longer the stretched rubber band, the farther the plane travels (expected).

The distances 180, 310 and 450 cm are sample numbers made up for practice. The textbook gives only an empty table for you to fill in.

Write a conclusion for an investigation where a 30 cm stretch gave 450 cm and a 10 cm stretch gave 180 cm.

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The longer the stretched rubber band, the farther the distance travelled by the paper plane. The hypothesis is accepted.

Why is the breathing rate higher after exercise? Give an inference.

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Because the body needs more oxygen after exercise (textbook answer).

A man bent over with a towel round his neck, catching his breath after exercise — Rate of breathing is higher after exercising.

Pictures: Science Year 5 (DLP) textbook, pp. 1–18 (tarik upih p. 1, folding steps p. 2, rubber band steps p. 6, measuring p. 7, soap bubbles p. 8, soap solution p. 10, breathing p. 15). Line graph drawn for this site from the textbook table on p. 13.

Summary

Skill	In one line
Observing	Use the senses to collect information.
Classifying	Group by a shared characteristic.
Measuring and using numbers	Numbers with standard units.
Making inferences	Sensible reason for an observation.
Predicting	What will happen next, from evidence.
Communicating	Share with tables, charts, graphs, words.
Using space-time relationship	How something changes with time.
Interpreting data	Explain patterns in a table or graph.
Defining operationally	Say what you do and measure.
Controlling variables	Change one thing, keep the rest the same.
Making a hypothesis	The more X, the more Y (testable).
Experimenting	Carry out a fair test and conclude.