Lesson 6

Elapsed Time

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
X
  1. 17 −  9 = 8
  2. 8 + 9 = 17
  3. 9 +  9 = 18
  4. 10 + 8 = 18
  5. 17 − 7 = 10
  6. 16 − 6 = 10
  7. 10 + 4 = 14
  8. 10 + 5 = 15
  9.  9 + 7 = 16
  10.  9 + 6 = 15
  11.  8 + 6 = 14
  12. 14 −  8 = 6
  1. Possible strategy: I know 6 + 6 = 12. To get 14, I need 2 more.
    So 8 + 6 = 14.

Ongoing Assessment

Use DPP item V to assess students’ abilities to determine the unknown number in an addition or subtraction sentence involving three whole numbers for the facts in Group F [E13].

V. Fact Families Quiz: Group F

  1. 17 − = 8
  2. 8 + 9 =
  3. 9 + = 18
  4. + 8 = 18
  5. − 7 = 10
  6. − 6 = 10
  7. + 4 = 14
  8. + 5 = 15
  9. + 7 = 16
  10. + 6 = 15
  11. + 6 = 14
  12. 14 − = 6
  1. Show or tell how you solved Question K.