These resources have all been created/posted by CAS Master Teachers and I have tried to pull them together into a learning sequence. The screencasts from the RSE and BCS are excellent and well worth watching. The Itchy Art and Music Player exercises are a great way to introduce algorithms and programming. I think all the exercises would be suitable for KS2.
Start with the tutor guide and screencasts here...
This is a good way to introduce and learn the key vocabulary used in Scratch, also has links to a useful resources site: https://community.computingatschool.org.uk/resources/2536/single
Starting with Scratch here: https://community.computingatschool.org.uk/resources/1174/single
is another useful introduction (using Scratch 1.4 which is possibly easier for Primary teachers)
A useful prompt sheet for the most-used blocks is here: https://community.computingatschool.org.uk/resources/3629/single
And a poster of Scratch 2 commands can be found here: https://community.computingatschool.org.uk/resources/5186/single
Practise (also useful for top-end KS2) with ‘Itchy
Scratch for independent learners has a set of exercises from CodeClub introducing the main elements of Scratch:
And here is a simple Scratch exercise: https://community.computingatschool.org.uk/resources/1205/single
Some lessons to try out ...
Year 3 – Scratch Music Player: https://community.computingatschool.org.uk/resources/3715/single
Finally, have fun with this Christmas Quiz exercise: https://community.computingatschool.org.uk/resources/4797/single