You do not know how many white marbles are in the jar.
Possible number of marbles in a jar.
The jar is filled with all white marbles.
You have 20 black marbles in your pocket.
You also get enough marbles to fill up the jar and store them in a bag or another jar tupperware container.
How many marbles are in the jar.
Basically at the end of class depending on the behaviour and observed effort of the students you add a certain number of marbles to the jar.
Assuming marbles with diameter 1cm 0 394 inches that s a volume of 0 524 cubic centimetres or about 0 032 cubic inches.
There is a contest.
Or if this is too much work you can try counting the number of marbles at the bottom or at the top and then counting the number of rows there appear to be.
Either way good luck.
It depends on the size of the marble.
The more marbles you add the better behaved focused and on task the students were.
A quart is 946 353 cubic centimetres or 57 75 cubic inches.
Who ever can calculate the closest to the actual number of marbles in a jar wins.
You can put in and take out marbles if you want to but you can not count the marbles nor do the base x the height.
Dividing by the volume.