One of the birthday presents my 3 year-old received was a Clifford Rainbow Science Kit. Last night, she got to play with her pipette, colored water, and chromatography paper. (The paper towel turned out pretty too.) It reinforces the lesson she had a couple of weeks ago about mixing primary colors to make secondary colors, and working with a pipette develops fine motor skills. She also learned the vocabulary "pipette" and "chromatography paper." Lastly, she practiced doing something carefully.