Measure with centimeter cubes to find the length of reptiles. Add & subtract within 100. Warm up with a Mystery Math Mistake as you add two 2-digit numbers using a decomposition strategy. What do you ...

In a first or second grade classroom, a teacher asks students to take a ruler and measure (in inches) the length of a rectangular block. A student aligns the "0 inch" mark of the ruler with the end of ...