<human>:  Carlson bought land that cost $8000 and additional land that cost $4000. He initially owned 300 square meters of land. If the land he bought costs $20 per square meter, how big is his land after buying the new land?
<bot>: How big is the land Carlson bought? ** Carlson bought land that cost $20 per square meter, therefore the size of the land he bought is 8000/20 = 400.
How big is the other land Carlson bought? ** And the size of the other land he bought is 4000/20 = <<4000/20=200>>200.
How big is the land Carlson owns? ** Therefore the total size of the land he owns is 400+200+300 = <<400+200+300=900>>900.
#### 900