In everyday speech, the aspiration of the unvoiced plosive phonemes /t/ and /k/ can sometimes be lost when they follow /s/ and a child may pronounce “st” as /sd/, e.g. saying sdop instead of stop, and “sc” or “sk” as /sg/, e.g. saying sgaf instead of scarf.
Playing games, like this version of /st/ /sc/ noughts ...