[NumLock]

Ildar-tsr:

function IntPower(const Base: Extended; const Exponent: Integer): Extended;

Код:

unit Math;

function RoundTo(const AValue: Double; const ADigit: TRoundToRange): Double;
var
  LFactor: Double;
begin
  LFactor := IntPower(10, ADigit);
  Result := Round(AValue / LFactor) * LFactor;
end;

function SimpleRoundTo(const AValue: Double; const ADigit: TRoundToRange = -2): Double;
var
  LFactor: Double;
begin
  LFactor := IntPower(10, ADigit);
  Result := Trunc((AValue / LFactor) + 0.5) * LFactor;
end;

--

Код:

uses
  UMathServices,

  Memo1.Lines.Add(ulSub('212.53', '212.49'));
  Memo1.Lines.Add(ulSub('212.053', '212.049'));
  Memo1.Lines.Add(ulSub('212.4556565', '212.343676676'));