I've been following a blog called Growing a Jeweled Rose for inspiration on activities to do with my girls. She has two daughters as well, and they are each a few months older than my girls, so I feel like her activities have all been 'tried and tested' for little girls like mine, and I can see a few months ahead into what kinds of activities will be appropriate for my girls' ages. Here is her post on the Squirty Sidewalk Chalk that we attempted a few weeks ago.
I used only 3 colours because I had 6 bottles and wanted each colour in baking soda paint AND vinegar paint, for mixing. Also, my girls haven't done a lot of primary colour learning, so this seemed like a good opportunity to do that.
Ingredients: Baking Soda, Corn Starch, Paint/Food Colouring/Liquid Watercolours, Vinegar, Water.
You also need some squirt bottles and a sidewalk or driveway on which to squirt the paint!
The first three bottles I filled about 1/3 with corn starch, and 1/3 with baking soda, then added a splooch of paint and filled the rest with water. Then I put my finger on the tip of the squirt lid and shook them until everything was mixed together. Once the dry ingredients had started to dissolve in the water, I was able to add quite a bit more water to fill the bottles. This was the squirty chalk paint, and I made one each of red, blue and yellow. I labelled the bottles with a big 'R', 'B' and 'Y' also, since I couldn't see the colours through the bottles.
Next, I divided the vinegar I had into the remaining three bottles and added another splooch of each colour paint and shook those until they were mixed and started foaming out the top of the bottles.
Made a mess of my deck.
I gave the girls the three chalk bottles and let them make designs all over our driveway. The concrete is in really bad shape, but it did what we needed it to. They were less interested in drawing pictures (or, squirting pictures, as I suppose they would be doing) and more interested in watching the liquid run down the slope of the driveway. They had fun squirting the colours together and watching them blend into one big puddle.
When they had emptied the chalk bottles, we walked around a bit and talked about the different colours. I noticed that the thinnest layers of paint had dried very quickly, and they looked just like chalk!
Then I let them loose with the vinegar. The vinegar reacted with the chalk paint - even the spots that had already dried - and fizzed up into a new colour (unless they squirted blue on blue, etc. which they did often because they seemed to be kind of missing the point). They again were less interested in the point of the experiment - colour mixing - or the fact that it fizzed - than creating more giant 'oceans' of puddle together. I let it be and decided that the entertainment was worth it anyway, and we could try it again later in the year - or next year - and it would certainly still be fun!
The paint in the vinegar didn't quite mix perfectly, although it worked well enough. I think liquid food colouring, or liquid watercolour would have worked a lot better. Next time.
This was where the blue and yellow paint had overflowed on my deck. The girls had fun making paint footprints. It's an old deck that is scheduled for demolition as soon as possible, so I definitely didn't care about the mess. As it happens, a few weeks later the deck is completely clean - everything washed away perfectly, in case you were worried!