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Third Grade Science Study Guide: Nature of Science

Part One

Vocabulary

1. Problem - the question

2. Question - something asked in order to find out something

3. Hypothesis - prediction about what you think will happen

4. Predict - to state what you think will happen based on observations

5. Investigate - observe and experiment using the process skills to find the answer to the problem

6. Observing - use the five senses to find out about objects and events

7. Measuring - use appropriate units to determine length, area, volume,

time, weight, and temperature

8. Experiment - a test or trial carried out under controlled conditions

9. Variable - any factor that can change in an investigation to affect an outcome

10. Results - something obtained by investigation

11. Conclusion - what you learned from your investigation

12. Repeated Trials - doing an experiment over and over again

13. Mass - the amount of matter in an object

Information

1.  Safety

2. Scientific Process

·  A PROBLEM is a question you want to investigate. Investigate means to look for the

answer.

·  Before you begin an investigation, you make a HYPOTHESIS about what you think will

happen.

·  The INVESTIGATION is the experiment. The investigation is the activity that gives you the

results (or the answer).

·  The CONCLUSION is what you learned from the data you collected during the experiment

or investigation. Data means the same thing as information.

·  When you CLASSIFY objects, you sort them into groups based on their likenesses and/or

differences.

·  Any factor that can change during an experiment to affect an outcome is a VARIABLE.

·  Doing an experiment multiple times is an example of REPEATED TRIALS.

·  The RELIABILITY of an experiment can be made better by using repeated trials and

making sure there is only one variable.

3. Variables

·  When you do an experiment, only one variable, or factor, in the experiment can change. All other variables must be controlled (kept the same).

·  For example, if you tested how fast a rubber ball would roll on sand and roll on wood, you must control the variable by using the same rubber ball (variable) for each test. The sand and wood would be the variables, or factors, that are changed.

MOLDY BREAD EXPERIMENT

·  PROBLEM: Will wheat bread grow mold faster than white bread?

·  HYPOTHESIS: I think the white bread will grow mold faster because I can see the mold on

it.

·  INVESTIGATION: Place a slice of wheat bread in a baggie, spray with water, and leave

on the counter for one week. Place a slice of white bread in a baggie, spray with water,

and leave on the counter for one week. See if mold grows faster on one of the bread

slices.

·  CONCLUSION: Mold grew faster on the wheat bread, so it does not last as long as white

bread.

MOLDY BREAD EXPERIMENT

·  The VARIABLE, or factor, that changes in this investigation is the type of bread.

·  The variables, or factors, that do not change are the light, water, and baggie.

·  A student can improve the investigation by doing it more than once. This is called repeated trials.

·  Doing a repeated trial and making sure everything else is the same (the amount of water and the size of the bread slices) will increase the reliability of the investigation.

·  Use the chant to remember the scientific process.

First I think of the problem. “What do I want to know?”

(point to your head with index finger)

Then I make a hypothesis. “I think so!”

(place hand over heart)

Next, I investigate to find out if I’m right.

(mime holding a magnifying glass and looking back and forth)

Finally, the conclusion, the answer is in sight!

(put hand to forehead flat as though looking for something)

4. Tools

5. Classifying

·  To classify objects, you group them according to similarities and differences.

6. Linear Measurement

·  Metrics is a measurement system used by most countries of the world.

·  The little finger is about 1 centimeter wide. (100 cm = 1 m)

·  The height of a doorknob is about 1 meter. (1000 m = 1 km)

·  The distance from school to the grocery store is about 1 kilometer.

This crayon is 4 centimeters long. In the second picture, the crayon is not placed at zero. To

find the length, draw a loop from the 2 to 3 and say 1, draw a loop from the 3 to 4 and say 2,

draw a loop from 4 to 5 and say 3, continue until you reach the end of the crayon.

7. Mass

·  Mass is the amount of matter in an object.

·  A balance scale can help you find the mass of an object. It can also help you compare the masses of objects.

·  The mass of a large paper clip is about 1 gram. (1,000 g = 1 kg)

·  The mass of your math book is about 1 kilogram.

Prefixes

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Abbreviations

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Units

kilogram / kilo / kg
gram / g / 1,000 g = 1 kg
/ This balance scale is evenly balanced. The
block has a mass of 20 grams.
/ The side with the crayon is tilting up. The crayon has a mass less than 20 grams.
/ The side with the apple is tilting down. The apple has a mass greater than 20 grams.
/ The side with the apple is tilting down. The apple has more mass than the block.

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