I can't remember the name of the story, but it was about a boy whose grandfather was a mad scientist. Boy had everyday problems, and his grandfather would give him his "inventions," which were relatively tame in sci-fi terms.
The best story inside was about a boy going camping in the woods with his class and his mother packing his backpack so heavy that he could barely lift it. So he goes to see his grandfather, who gives him small "satiation pills," one pill equaling one meal. He then goes camping empty-handed, discarding everything, and everyone is envious of him not being tired, yada-yada. They march through the woods for several days. So, on the last day of camping, he gets lost in the woods with the girl after rock sliding (?) occurs. They have no food except for the boy's pill. They had started a campfire and were sitting around it while hungry. While looking at the girl who was almost crying, the boy realized why his mother was right. He quickly makes a fake pill out of the edible grass nearby and gives the real pill to the girl while eating the fake. The girl was overjoyed, and they camped for the night. The following day, the group locates them and they return home. After that,the boy tells to his grandpa what he did in while camping, and usual morale of the story scene occurs, the end.
It's was pretty memorable, considering it is almost 20 years since I read it in my grandma's house and I still remember it.