A bacteria culture begins with 4 bacteria which double in size every hour. How many bacteria exist in the culture after 8 hours?

It begins with 4

After 1 hour = 4 x 2 = 8

2 hours = 8 x 2 = 16

3 hours = 16 x 2 = 32

4 hours = 32 x 2 = 64

5 hours = 64 x 2=128

6 hours = 128 x 2=256

7 hours = 256 x 2 = 512

8 hours = 512 x 2 = 1024

Answer: 1024

After one hour: 8

after 2 hours: 16

after 3 hours 32

after 4 hours 64

after 5 hours 128

after 6 hours 256

after 7 hours 512

after 8 hours 1024