Aircraft maintains constant CAS = 1/2rho V2
An increase in temperature will decrease density Rho ?
To maintain CAS V must increase! This is TAS
An increase in temp will increase LSS ! Mach no
=TAS/LSS both have gone up. Mach number stays the same.
You could input the data on your CRP5 to prove this with actual figures example
FL 150 OAT 0 CAS 170 = TAS =220 LSS = 645
220/645 =M0.34
Fl 150 OAT +25 CAS 170 = TAS 230 LSS = 675
230/675 = M0.34