If you look at the numbers past the decimal point, the first digit - 8 - is in the tenths place. So, - 7 - is in the hundredths. What number is beside that? 4. When you round four, does it go up to ten or down to zero? Which is it closer to? The answer is zero.
So, the 7 in the hundredths place stays the same and any numbers after it are turned to zeros and cut off. Ending up with 26,379.87
1/2 of 10 is 5 so the answer you are looking for is 5 cookies
You can fit 15 2cm in a 600mm by 500mm.
2 + 2 + 2 + 2 + 2 = 10
Five days
2 + 2 + 2 + 2 + 2 + 2 + 2 = 14
Full week
10 x 2 = 20
14 x 2 = 28
The bacteria will double every day for a total of 20/28 bacteria on the last day.