Josh uses his brain
Josh smartly identifies that physically counting every single grain would be a ridiculous endeavour, so he uses the kitchen scale to figure out that, if 250 grains of rice weigh 5 grams, then a 500 gram bag of rice should contain approximately 25,000 grains of rice.
Back in the studio, having been singled out to complete menial tasks three times for the episode, Josh makes the case that he deserves at least one point for his efforts.
Note: later in the episode, Greg does decide to award Josh one point for his work on this and two other solo menial tasks, meaning he effectively earned one third of a point for this.
(Written by Karl Craven)
(Illustrations collected and adjusted by: Karl Craven)