Try some technology: Pasco

I use both Vernier and Pasco sensors.  If you have an iPad, you can download tons of free labs called SPARKlabs.   The Pasco sensors require an interface. The Airlink2 is a Bluetooth device for the iPad.  The Pasport sensors lock into the Airlink2 to collect data.  Where to begin?  Try a temperature probe. I have had good luck buying used sensors.  The Pasco user guide explains how to use the probe.  Here are some ideas for elementary science labs once you get the hang of the probe.