Leslie's Great-Grandma Pat received a total of 93 birthday cards.
Leslie and Grandma Pat opened 36 cards and decided to leave 57 cards for later.
To determine the total number of cards, we can add the number of cards opened and the number of cards left unopened:
Total cards = Cards opened + Cards left unopened
Total cards = 36 cards + 57 cards
Total cards = 93 cards
Therefore, Leslie's Great-Grandma Pat received a total of 93 birthday cards.
Complete question:
Leslie's Great-Grandma Pat is turning 100 years old! The family throws her a party, and Marshall helps her open a large stack of birthday cards. After opening 36 cards, they stop so Grandma Pat can blow out the birthday candles. Marshall and Grandma Pat leave the remaining 57 cards for later. Find the total number of birthday cards in the stack.