Arithmetic Grade One

Lesson One hundred seventy-three: SUBTRACTING TENS

  

  
  

   9 TENS - 7 TEN = 2 TENS

   2 TENS = 20
  


  

  
  

   8 TENS - 4 TENS = 4 TENS

   4 TENS = 40
  


  

  
  

   5 TENS - 4 TENS = 1 TEN

   1 TEN = 10
  

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.