Answer:
0.64
Explanation:
Given: Craig has a box of chocolate with 5 rows in it.
Each row has 20 chocolate.
Craig and his friends eat 64 chocolate.
As given, we understand that there is box of chocolate with 5 rows and each row have 20 chocolate, therefore we can find total number of chocolate.
Total number of chocolate=

∴ Total number of chocolates in box= 100.
Now, we know craig and his friends eat 64 chocolate.
∴ To find decimal of number chocolate eaten out of 100 chocolate, we need to put numbers in fraction first then convert it in decimal.
Number of chocolate ate by craig and his friends is

∴ Craig and his friends eat 0.64 chocolates.