Here's a fun project that the kids can help make and then enjoy for weeks to come—making their own play dough. Mix two cups of flour, ½ cup of salt, and four tablespoons of cream of tartar in the slow cooker. After that, pour in two cups of water, two tablespoons of oil, and a bit of food coloring. Place a damp towel under the lid, and cook the colorful mess on high for 45 to 60 minutes, stirring often.When done (the dough should easily form a ball), remove the mixture from the slow cooker, knead several times, and allow it to cool. When stored properly, the playtime essential should last three to four months.