OMG 🙈 im so confused

Calculating the lux.

I have identified the amount of lux needed.

im on step 2 now, workout the area of the room by x both sides

so im taking the measurements from my floor plan which is 4950mm x 2890mm

im then trying to convert it to scale to meters, but the answer im getting does not seem right at all.

I can feel im doing something wrong. haha

please help haha.