If you teach children in the primary grades, you’ll enjoy this new series from the wonderful Steve Wyborney. Every day for the rest of the school year, Steve will post a new estimation or number sense resource for grades K–8 (or any age!) at his blog:
“This is my way of providing support and encouragement – as well as bringing math joy to your classroom… I’m going to stick with you all year long.”
—Steve Wyborney
Denise Gaskins' Let's Play Math 