They wrote their estimates on a sticky note which they then placed on a number line in the approximate place their number would be. For this jar, they placed their estimates between 20 and 50. The special helper then counted the poker chips and there were 27.
Having a wide variety of learners means that lessons have to be accessible to all students. They had to choose which number lines suited them and could adapt the level they chose depending on their success as they proceeded to work through the cards. The following learner chose 2 pink cards and then challenged themselves to yellow cards. Each student then made MY NUMBER LINE on the bottom of their sheet, which I copied for all the students to do the next day. They really enjoyed working to complete each other's number lines.
These types of activities reinforce the concepts of ordering, printing, comparing and estimating numbers, as well as counting by 1s, 2s, 5s, 10s and 100s.