Question

a petri - dish originally contained 637 bacteria. a scientist let the bacteria grow and now there are 841 of them. how many more bacteria are there now?

Explanation:

Step1: Identify the operation needed

To find out how many more bacteria there are now, we subtract the original number of bacteria from the current number.

Step2: Perform the subtraction

Let the original number of bacteria be 637 and the current number be 841. The calculation is $841 - 637$.
$841-637 = 204$

Answer:

204