Arithmetic Grade One

Lesson One hundred sixty-five: ADDING TENS

  

  
  

   2 TENS + 1 TEN = 3 TENS

   3 TENS = 30
  


  

  
  

   2 TENS + 7 TENS = 9 TENS

   9 TENS = 90
  


  

  
  

   5 TENS + 3 TENS = 8 TENS

   8 TENS = 80
  

NOTE: Have the student count the sticks of ten by counting by tens. Practice a few more problems like these before going on to the activity.