These follow up 1-10, with progression of certain skills, while also continuing to review.
They tend to follow a best math practice strategy: concrete - pictorial - abstract.
Again, teachers have the freedom to use as review, morning starters, as part of a lesson showing connections among skills (another best math practice) rather than isolation of skills!
With ruler, students can either locate the digit or draw a line segment that measures its number.
I also observe, as many of you probably do too, confusion when it comes to the TEEN numbers. These activities allow opportunities to focus on them while teaching skills simultaneously. I encourage to use as a supplement to a small group activity, teaching or reteaching concepts.