My oven dial has no numbers, just 1 through 7 - which one is 350?

On a 1 to 7 dial, 350 usually lands somewhere around 4, maybe a nudge past it. But treat that as a rough guess only, because the printed numbers on old dials were never that precise and the thermostat inside drifts after decades of use. Your 4 could actually be holding 325 or it could be pushing 400, which would explain the carnage. So yeah, get the oven thermometer, it's the only way to sort this out. Put it in the middle of the center rack, let the oven run a good 30 minutes after the preheat light clicks off, then read it. Nudge the dial a bit, wait 20 minutes, read again. Do that at a few settings and you'll have the whole dial mapped out in an afternoon. Write the real temps on tape next to the numbers and you're done guessing. Don't trust the first reading right when it says it's preheated, older ovens take a while to actually settle.

That pizza coming out burnt on one side and cold on the other is a seperate issue though. That's a hot spot, not a dial problem. Every oven has one, old ones especally. Easy test: scatter a thin layer of white flour on a sheet pan, put it on the rack, and see which areas brown first. Once you know where the hot zone is, rotate pans halfway through baking and avoid that rack position for anything delicate like cookies. Also pull the knob off and look behind it. On some stoves the numbers are printed on the panel behind the dial and only the knob face is worn blank, or there's a separate plate that's gone missing. And check for a model number sticker on the side of the door frame, under the cooktop edge, or on the back of the storage drawer. They hide in weird spots on old stoves, and with a model number you can order the exact replacement knob for cheap.

Been through this with a rented place years back, dial only said Low to High and nothing in between. I baked by time and look instead of trusting the number. Checked everything five minutes early, pulled stuff the second it looked right, and kept a little notebook of what worked at which mark. Old school but it saved me from more burnt suppers. Also worth knowing the oven cycles, it drifts up and down around the set point, so a thermometer will wobble a bit and that's normal. Do you know if yours is gas or electric? Gas ones with a standing pilot heat slower and cook a touch differently than you might expect.

So the flour trick works on a sheet pan but can you do the same thing with bread slices laid out instead? I tried it once and they toasted unevenly too, seemed easier to see than flour. Also mine has a gap in the door where the seal looks flattened out, you can feel heat coming out near the handle when it runs. Could that be making things cook wierd too, or does the inside stay fine anyway? I don't know if that matters or if I'm just noticing normal oven stuff.