cashier help!!!!

cashier help!!!! okay so i work at a grocery store, and i recently got trained on the cash register. i’m good at what i do, the only problem is saying the totals. for example, i cannot for the life of me say anything number that starts with forty, fifty or seventy. when i have to say a total with these numbers, i block for like 5-10 seconds. do you guys have any advice on what to do during these situations? thanks!