Unit of surface 
Name: ______________________________________ Subject: _______________________ Date: _______
Write on the right side what is missing.
1. The square meter.
The square meter is the area of a square whose sides measure exactly one meter. Its symbol is: m.^{2}.
2. Multiples of the square meter.
These are:
1 square decameter is equal to 100 square meters: 1 dam^{2} = 100 m^{2} .
1 square hectometer is equal to 100 00 square meters: 1 hm^{2} =
100 00 m^{2}.
1 square kilometer is equal to 100 00 00 square meters: 1 km^{2} =
100 00 00
m^{2}.
1 square myriameter is equal to 100 00 00 00 square meters: 1
mam^{2} = 100 00 00 00 m^{2}.
To measure fields, we use agricultural units. These are:
1 hectare is equal to hm^{2}: ha = hm^{2} = 100
00 m^{2}.
1 area is equal to dam^{2}: a = dam^{2} = 100 m^{2}.
1 centiare is equal to m^{2}: ca = m^{2} = 1 m^{2}.
The units of surface increase and decrease from 100 to 100.
The superior unit is 100 more than the lower.
It answers these questions in square meters:
6 hm^{2} = 
3.  Submultiples of the square meter
These are:
1 square decimeter is equal to 0.01 square meters: 1 dm^{2} = 0,01 m^{2}. 1 m^{2} has
100 dm^{2}.
1 square centimeter is equal to 0.0001 square meters: 1 cm^{2} =
0,00 01 m^{2}. El m^{2} has 100 00 cm^{2}.
1 square millimeter is equal to 0.000001 square meters: 1 mm^{2} =
0,00 00 01
m^{2}. El m^{2} has 100 00 00 m^{2}.
The units of surface increase and decrease from 100 to 100.
The lower unit is 100 less than the superior.
It answers these questions in square meters:
5 dm^{2} = 
4. Conversion of unit
Each unit of surface is 100 times greater than the immediate lower and 100 times less than the immediate superior.
To convert from dam^{2} to
m^{2}
we multiply by 100 or we move the decimal point two places to the right.
Examples: 7 dam^{2} = 700 m^{2}; 73,25 7 hm^{2} =
73 25,7 dam^{2} = 73 25 70 m^{2}.
To convert from m^{2} to
dam^{2},
we divide by 100 or we move the decimal point two places to the left.
Examples: 3 m^{2} = 0,03 dam^{2}; 14 68 m^{2} =
14,68 dam^{2} = 0,14 68 hm^{2} = 0,00 14 68 km^{2}.
It answers these questions in square meters::
235 cm^{2} = 
5. Converting from complex to noncomplex
To convert from surface complex to a noncomplex of lower order, we write the numbers of successive orders, reserving two places for each order and placing zeros in the empty places.
Example: 5 hm^{2}, 18 dam^{2} and 25 m^{2} can be written as: 5 18 25 m^{2}
It answers these questions in square meters:
3 ha, 7 a y 2 ca = 

8 km^{2}, 17 dam^{2}, y 3 dm^{2} = 

41 hm^{2}, 25 m^{2} y 7 cm^{2} = 
6. Converting from noncomplex ( 1 25 m^{2} ) to complex ( 1 dam^{2} and 25 m^{2} ).
To convert from surface noncomplex to complex, we separate the numbers in pairs, from the decimal point in both places (before and after the decimal point), putting the corresponding names to their orders.
For example: if the area of a field is 60 26,21 8 m^{2}, we complete the orders 60 26,21 80 m^{2}, and then it can be written as: 60 dam^{2}, 26 m^{2}, 21 dm^{2} and 80 cm^{2}.
Examples:
30 00,02 m^{2} = 30 dam^{2} and 2 dm^{2}
73 00 00,00 00 31 m^{2} = 73 hm^{2} and 31 mm^{2}.
5,7 mam^{2} = 5 mam^{2} and 70 km^{2}.
7. Problems.
Do these problems on a paper and write the solution:
1. If the m2 of a land cost 2 euros, how many money will I pay if I buy a land of 7 ha? 

2. One province is 14725 km^{2}. How many areas are there? 

3. A field of 12350 m^{2} is divided into four equal parts. How many dam^{2} does each part measure? 

4. The floor of a room is 15.598 m^{2} and has 55 floor tiles. How many cm^{2} does each floor tile measure? 

5. A courtyard has 25 rows of tiles with 37 tiles each one of them. The courtyard is 1 dam^{2}, 66 m^{2} and 50 dm^{2}. How many dm^{2} does each tile measure? 

6. How many standing people can be on a courtyard of 3 dam^{2} and 60 m^{2} if each person occupies an area of 20 dm^{2}? 

7. We have a farm and we have sold 2/5 to 0.33 euro per m^{2} and the rest of the farm have sold to 30.1 euros per dam^{2}. How many money did we obtain from the sale? 

8. On day of rain, 82 liters of water have fallen in a square meter. How many hectoliters of water have fallen in a field of 25 ha and 87 a? 

9. The surface of the Earth is 5101000 mym^{2} and 3/4 is occupied by the oceans. How many km^{2} do the continents take up? 

10. The largest island on earth is the Greenland and it measures 2180000 km^{2} and one of the smallest island is the Cabrera that has 2000 ha. How many times does the Cabrera fit in Greenland? 
 Educational applications 
Mathematics 
In Spanish  Interactive
®Arturo Ramo García.Record of intellectual property of Teruel (Spain)
No 141, of 29IX1999
Plaza Playa de Aro, 3, 1º DO 44002TERUEL