Unit 1, Lesson 34# Model n – n and n – (n – 1) pictorially and as subtraction sentences.

EngageNY 60 min(s)

In this lesson, students use Rekenrek bracelets and simple math drawings to show subtracting a number 1-10 from itself (n - n), and taking away one less than a number from the number (n - (n - 1)), and create number sentences to represent each situation. As they work, they make observations such as, "When I take 5 away from 5, I'm left with 0 every time