Electricity (#32 I think there are 2 of them) is excellent. Corn and beans too. Metric measuring was fabulouxs as well, we did it along side Life of Fred Decimals and Percents. Weighing was fidgety; we were trying to use the scale to do the Density book, but it didn't work well. Density is good though. Get a Grip and Intermediate Lentil Science are also great, though Lentil contains all of Get a Grip; wish I hadn't bought both. Balancing is good too. Pendulums was fussy too...