While loop/half-life

[Miraclefruit]

Carbon-14 is constantly produced in Earth’s upper atmosphere
due to interactions between cosmic rays and nitrogen, and is found in all plants and animals.
After a plant or animal dies, its amount of carbon-14 decreases by about .012%
per year. Determine the half-life of carbon-14, that is, the number of years required for
1 gram of carbon-14 to decay to less than ½ gram

I have to use while statement but I'm not sure how to do that without just using the formula? 
Any tips on the math for this problem?

[micseydel]

What have you tried?

[Miraclefruit]

i wasthnking divide by 0.012%? or keep multplying by 0.0988% in the while loop

[ichabod801]

Okay, but what's the condition on the while loop going to be?

[Miraclefruit]

Okay, but what's the condition on the while loop going to be?

while (carbon > 0.5)?

[sparkz_alot]

You're going to have to show more than a tentative first line.

while carbon > .5:
    # make some computations

The thing about learning is to try something and see if it works as expected, if it doesn't work, try something else.  Speaking for myself, I have more failures than successes.

[nilamo]

Speaking for myself, I have more failures than successes.

100 failures could lead to one success.  ...and, once successful, you stop working.  The default state of any sort of engineering is that failure_count > success_count.