After having them copy, sort, and read in isolation all those /er/ words, give the students a chance to demonstrate their skills of recognizing /er/ patterns in context!
Here's an original story full of words spelled with er, ir, ur, and wor. Students should be able to decode all these words after practicing the patterns in class. You could even use it for close reading or to develop vocabulary. They can even find the words and sort them into groups on the back!
I usually give away everything