`8` `200` `cm^2 = 82` `dm^2`

`1` `dm^2=  100` `cm^2`

`=> 1` `cm^2 = 1/100` `dm^2`

`=> 8` `200` `cm^2 = 8` `200 xx 1/100 = 82` `dm^2`

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`2` ha `500` `m^2 = 2,05` ha

`1` ha `=10` `000` `m^2`

`=> 1` `m^2 = 1/10000` ha

`=> 500` `m^2=  500/10000 = 0,05` ha

`=> 2` ha `500` `m^2 = 2+0,05 =2,05` ha

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`7` `m^2` `400` `dm^2` `= 11` `m^2`

`1` `m^2 = 100` `dm^2`

`=> 1` `dm^2 = 1/100` `m^2`

`=> 400` `dm^2 = 400xx1/100 =4` `m^2`

`=> 7` `m^2` `400` `dm^2 = 7+4=11` `m^2`