Truncation is new to the National Curriculum and the GCSE and there aren’t many resources out there (textbooks or worksheets).
I found a decent presentation by Rory Mathews, with some handy quick-fire questions on it. It comes with a worksheet, but there is only a handful of truncation questions on the worksheet before it goes into rounding, so I’ve made a very simple worksheet with practice questions on truncating and writing the error interval for a truncated number.
After spending time on the basics, we’ve done this really nice activity by Peter Mattock which pretty much finished off the topic (apart from all the times we’ll revisit to stop them forgetting, of course!)
That’s it. An appropriately short post I hope.