Find the closest precision... 1)Start with 1*1 and 2*2. 2)Check it 5 is between 1 and 4. 3) It's not, then try 2*2 and 4*4. It is between 4 and 16. 4) Difference between 2 and 4 above is 2. 5) Half the difference (2), which is 1 and check between 2*2 and (2+1)*(2+1) and (2+1)*(2+1) and 4*4. 6) Keep looping back to step5, like 2.5 and 3, 2,5 and 2.75, etc... until you find the closest value.