I think you are thinking of the phrase  the other way around , which does essentially mean the opposite, but in a specific way. The specific nature of the other way around is that it means that doing what you say in the opposite direction is correct, not necessarily the exact opposite.
Once kittens reach 4 weeks of age, their mother usually begins to wean them off milk and onto solid foods. Because the weaning process can take up to six weeks, purchase a small amount of kitten milk replacement formula and mix it into your kitten's food during his first two weeks with you.
Feed the kittens. If the mother cat is not around or is unable to care for her kittens, you will need to prepare their food for them and feed them yourself. The type of food that you prepare for the kittens will depend on how old they are. Make sure that you ask your veterinarian about any special feeding needs your kittens may have.