Big Question: I can't win the battle over screen time with my grandchildren when they are at their house, but what are some toys I can provide when they visit that promote more creative thinking?
Good for you for accepting that as a grandparent, there are going to be lots of things that are out of your control. And, even better that you value play that encourages creativity, imagination and problem-solving.
Any block set, wooden or plastic connecting ones like Duplo or Lego, will provide hours of fun and definitely promote creative thinking.
I have never met a child that doesn't love "Magna-Tiles," which are magnetized plastic shapes that allow for lots of easy building and dramatic play. These materials, in addition to developing motor skills, encourage language development, experience with math concepts and the scientific method of observation and trial and error. The larger sets of "Magna-Tiles" can be quite pricy, but there are many less expensive brands available.
Least expensive of all is a collection of cardboard tubes, boxes and plastic containers that you can make available for building robots, doll houses and even whole cities. For a small investment in some heavy duty tape, you have the ingredients for hours of creative fun.
Here's to more inventive play!