You could play this game for a whole class period, but it’s also a great time filler – you can play a round or two in the minute while you’re waiting for the bell to ring after finishing the day’s lesson.
Depending upon what you’re currently studying and/or how advanced your students are, you can have them estimate length, mass, and/or volume.
Pick an object at random and have students its length, mass, or volume. Students write down their estimation on a scrap piece of paper (you can collect these if you’d like, but I usually don’t, we just compete for bragging rights). You then determine the actual length/mass/volume.
The more you play, the better your students will get at estimating measurements.
If your students need more of a challenge, you could change up the units you want them to answer in… height of the table in mm, for example.
You can find a similar game here. She uses it as a team event – sounds like fun!