To find the ratio of children to keychains, first determine the total number of keychains. Each of the 6 children has 2 keychains, so:
Total keychains = Number of children × Keychains per child = 6 × 2 = 12 keychains.
Now, the ratio of children to keychains is:
Children : Keychains = 6 : 12.
This can be simplified to 1 : 2. However, since the original ratio is asked for, the correct answer is:
6:12 (ratio of 6 to 12).