Log[10,2.^24]

Log[10,2.^53]

3.141592653589793

(N[Pi,45]-SetPrecision[3.141592653589793,40])/N[Pi,45]

(N[Pi,45]-3.1415927)/N[Pi,45]

2.^1000

(SetPrecision[12345678901234567890,100]-SetPrecision[1.234567890123457 10^19,100])/SetPrecision[12345678901234567890,100]