مقدمة إلى الآلات البسيطة من K'NEX(R): التروس - بناء 7 نماذج

My 7-year-old finally understood how gears work after building the crank model—the plastic pieces click together firmly and the instructions are clear enough for him to follow alone.

The 7 model builds kept my third graders busy for a full afternoon, and the gears clicked together snugly enough that nothing fell apart mid-rotation. Watching them test the crank mechanism on the different models really made the science concepts stick.

My son built a working car and a hand mixer in one afternoon, and the included gear pieces are sturdy enough for his enthusiastic play. The instructions were clear enough for a 7-year-old to follow with just a little help. Just the right challenge for a curious kid.