I prepped my kiddos by telling them we were going to be Miner’s. We discussed what type of minerals they were mining for, got into groups of two, and each grabbed a bag! My spectacular aid went out into the field and clumped some of the rocks together and spread out others. Then we moved out to the field to “mine”.
After they had gathered as much as they could, we took their bags inside and sorted out our minerals into piles of gold, silver, and gypsum.
I went around and weighed their piles, using my bathroom scale, and had a worksheet ready for them to fill in, with their weights.