I seem to remember on the ZX81 using numbers took 5 bytes, so you could save a lot of memory by using inbuilt constants in stupid ways. So you wouldn't use 0,

I seem to remember on the ZX81 using numbers took 5 bytes, so you could save a lot of memory by using inbuilt constants in stupid ways. So you wouldn't use 0, you would use NOT PI Let a=NOT PI SGN PI for 1 COS PI for -1 etc. Those bytes counted when you only had 1K RAM.