Science Lab - Rain Gauge

We are implementing a science lab into our science program and I chose to try out Real Science Odyssey.  You can try before you buy and so we printed a bunch of labs to try and see if it fits K's learning style and my teaching style.  So far she is loving it and this week we are doing a rain gauge.  We made one from a 2-liter bottle and then K is charting each day how much it rains.  She predicts how much she thinks it will rain each day and then she will find out how much it actually did rain when she goes outside and checks it every morning.  She is so excited and has been looking out the window to check it for a while now lol.  She guessed 1 inch of rain by tomorrow morning - so we will see!