Real data needs several functions at once: clean the text, convert the type, then label or round the result. This set uses tickets, signups_raw, memberships, orders and products.
Build each answer from the inside out. Write the innermost step first (for example, TRY_CAST(age_text AS INTEGER)), run it to see the values, then wrap the next function around it. Remember the traps from the unit: text compares by its exact characters, whole-number division drops decimals, and NULL passes through most functions untouched.