A special struct for floating point numbers which allows higher accuracy

FixedFloat.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define DISPLAY_BUFFER_SIZE 5

typedef struct FixedFloat
{
    int upper;
    int lower;
    int numLowerDigits;
}FixedFloat;

FixedFloat createFixedFloat(int upper, int lower, int numLowerDigits)
{
    FixedFloat x = {.upper = upper, .lower = lower, .numLowerDigits = numLowerDigits};
    return x;
}

double getValueFromFixedFloat(const struct FixedFloat fixed_float)
{
    return fixed_float.upper + (fixed_float.lower / powf(10, fixed_float.numLowerDigits));
}

char * getStringFromFixedFloat(const struct FixedFloat fixed_float) 
{
    char * output = malloc(DISPLAY_BUFFER_SIZE);
    sprintf(output, "%d.%d", fixed_float.upper, fixed_float.lower);
    return output;
}

int main()
{
    FixedFloat y = createFixedFloat(123, 45, 2);
    printf("%f\n", getValueFromFixedFloat(y));
    printf("%f\n", 123 + (45 / powf(10, 2)));
    printf("%f\n", 123.);
    printf("%f\n", (45 / powf(10, 2)));
    printf("%s", getStringFromFixedFloat(y));
    return 0;
}