The 100 chart is a useful visual for basic mathematical concepts of more and less, and add and subtract. This unit is based on 1 more/less and 2 more/less. A 1-40 chart is included for the lower numeral problem pages as well as a 100 chart for higher numeral pages. This is a great tool for the classroom, special education, homeschool and distance learning. The design is favorable for all age groups. A fun extended activity reinforces the skills at the end of the unit.