oven
The French word for 'oven' is 'four'. It is used exactly like in English, specially in contexts relating to cooking or baking. For example, 'Je mets le pain dans le four' means 'I put the bread in the oven'.
I bought a new oven.
In this sentence, 'four' is used as a noun to refer to an oven, a common kitchen appliance for baking or roasting.
The bread is in the oven.
In this context, 'four' is also used as a noun to denote a place where something (in this case, bread) is being baked or cooked.
The oven heats to 200 degrees.
Here, 'four' is again used as a noun referring to an oven, a device used to heat up and cook food. It is accompanied by 'chauffe' which means 'heats', and 'à 200 degrés' meaning 'to 200 degrees'.