% expr 60.9-59.7
1.1999999999999957

#include <iostream>
int main()
{
    double a = 60.9;
    a -= 59.7;
    std::cout << "double a = " << a << std::endl;
    float b = 60.9;
    b -= 59.7;
    std::cout << "float b = " << b << std::endl;
}

double a = 1.2
float b = 1.2