It seems you have four phrases here: 1. "passing time", "marking time", "keeping track of time" Ex.: "He is passing time in the hospital by reading novels." Ex.: "The prisoner was marking time by saving one crumb for every day." Ex.: "The teacher was keeping track of time during the test and warned us when only ten minutes remained." 2. "as vast as the ocean"; very expansive; unlimited Ex.: "His potential to succeed is as vast as the ocean." Ex.: "The distance between their hearts was as vast as the ocean." 3. "mathematical logic" This is complicated. It is a whole system of how to combine numbers. Things like +, -, x, <, =, etc. are part of mathematical logic. 4. "memory"; ability to retain information; an experience that is remembered Ex.: "He has an excellent memory; he never forgets someone's name!" Ex.: "My computer has 500G of memory; it can store a large amount of information and files." Ex.: "I have good memories about our vacation house at the beach." I hope that was accurate and helpful.