Lesson 2

Subtraction Seminar

Est. Class Sessions: 2–3

Daily Practice and Problems

Teacher Notes
X

Make a sketch on the board to illustrate the problem. Have desk number lines and the classroom number line readily available.

  1. 54 grams;
    20 + 10 + 15 + 9 = 54

  2.  20  + 10 + 10 + 14 = 54


H. Make It Balance

  1. Jackie found the mass of a box of crayons by using the following masses: one 20 g, one 10 g, three 5 g, and nine 1 g.

    What is the total mass of the box of crayons? Write a number sentence for the mass.




  2. Tanya found the mass of a pack of markers. The mass was the same as Jackie’s crayons. Complete the number sentence for Tanya’s markers.

+ 10 + 10 + 14 = 54