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Question
You can play this game on the ground. Make two squares of one square meter each. Divide your class into two teams. Ready to play!
- How many of you can sit in one square meter?
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Solution
Three can sit in one square meter.
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RELATED QUESTIONS
Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity):
the number of strands of hair on your head
Write true or false.
Every measurement involves two things – a number and a unit.
500 gm = ______ kilogram.
Match the following.
| 1. | Length of the fore arm | metre |
| 2. | SI unit of length | second |
| 3. | Nano | 103 |
| 4. | SI Unit of time | 10–9 |
| 5. | Kilo | Cubit |
Fill in the following chart.
| Property | Definition | Basic Unit | Instrument used for measuring |
| Length | |||
| Mass | |||
| Volume | |||
| Time |
Metre is the unit of ______.
Guess the lengths to draw these things. Ask your friend to draw the same. After you make the drawing use a scale to measure the length. Whose drawing showed a better guess?
| Guess its length and draw |
Measure of your drawing |
Measure of your friend’s drawing |
| An ant of length less than 1 cm |
||
| Pencil of length about 7 cm |
||
| A glass 11 cm high with water up to 5 cm |
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| A bangle of perimeter 20 cm |
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| A curly hair of length 16 cm |

What is Dinesh’s height in metres? _____ m _____ cm.
How many stamps can be placed along its length?
Arbaz plans to tile his kitchen floor with green square tiles. Each side of the tile is 10 cm. His kitchen is 220 cm in length and 180 cm wide. How many tiles will he need?

There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.

- How many kilometers long is the actual boundary of lake A?
There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.

- Find the area of lake B on the drawing in square cm. What is its actual area in square km?
What are the materials needed to find the length of a banana?
What formula is used to measure the area of your classroom?
Give some examples of larger length measures.
What unit will you use to measure the length of our classroom?
The SI unit of mass is kg.
In an experiment to estimate the size of a molecule of oleic acid 1 mL of oleic acid is dissolved in 19 mL of alcohol. Then 1 mL of this solution is diluted to 20 mL by adding alcohol. Now 1 drop of this diluted solution is placed on water in a shallow trough. The solution spreads over the surface of water forming one molecule thick layer. Now, lycopodium powder is sprinkled evenly over the film and its diameter is measured. Knowing the volume of the drop and area of the film we can calculate the thickness of the film which will give us the size of oleic acid molecule.
Read the passage carefully and answer the following questions:
- Why do we dissolve oleic acid in alcohol?
- What is the role of lycopodium powder?
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- How will you calculate the volume of n drops of this solution of oleic acid?
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