Simple calculation fails

Projects Programming
1

Hi,

I'm embarassed to post this question here. But I am not able to calculate a common divider / multiplier operation. I'm stuck and I hope that someone can help me. I can't figure out that strange behaviour:

Here some tryouts. Result should be 35,98, or better 36 (%).

first try:

Serial.println((2913/8096)*100);
=> results in 0

second try:

char t[4];
float i = (2913/8096)*100;
sprintf(t, "%d", i);

Serial.println(t);
=> results in 0.

third try:

char t[4];
int i = (2913/8096)*100;
itoa((2913/8096)*100, t, 10);

Serial.println(t);
=> results in 0.

I've changed i to be float, int, long. Result is the same.

What am I doing wrong?! This is incredible I cant find my mistake :~

Thanks for your help guys

-Florian

2

Serial.println((2913L * 100L) /8096L); ?

3

Thank you. It works fine.

I've learned something new today :slight_smile: -> IntegerConstants!

4

Next step is to learn about float constants.

Serial.println((2913.0/8096.0)*100.0);

Will NOT print 0.

5

mesa:
Thank you. It works fine.

I've learned something new today :slight_smile: -> IntegerConstants!

And hopefully you've learned that dividing an integer by a larger integer will give you zero.