Translation:There are five desks.
The way the numbers (counters?) are being introduced here is so bad, especially with how in-depth the duo course is NOT going into the language so far. After hovering over 五つ and listening several times, I had to type ５つ into google translate just to figure out that it is いつつ. If the sentences had a slower option, as well as accurate definitions when hovering, this wouldn't be an issue.
Duolingo is best used in conjunction with other resources. Here is an explanation of counters for beginners. https://www.tofugu.com/japanese/japanese-counters-guide/