Your SlideShare is downloading. ×
  • Like
2-2 Mental Math: Using Compatible Numbers and Compensation
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Now you can save presentations on your phone or tablet

Available for both IPhone and Android

Text the download link to your phone

Standard text messaging rates apply

2-2 Mental Math: Using Compatible Numbers and Compensation

  • 5,587 views
Published

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads

Views

Total Views
5,587
On SlideShare
0
From Embeds
0
Number of Embeds
2

Actions

Shares
Downloads
70
Comments
0
Likes
1

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide











































































Transcript

  • 1. 2-2 Mental Math: Using Compatible #s and Compensation Math Notes Mathematical Reasoning 1.0
  • 2. Compatible Numbers Compatible numbers are numbers that are easy to compute mentally. 19 + 25 + 11 = 30 + 25 = 55
  • 3. Compensation Numbers Compensation involves deciding which number to adjust to make it easier to add or subtract. Compensate by changing the other number. 47 + 16 Add 3 Subtract 3 to adjust 50 + 13 = 63
  • 4. Compensation Numbers Compensation involves deciding which number to adjust to make it easier to add or subtract. Compensate by changing the other number. 73 - 38 Add 2 Add 2 to adjust 75 - 40 = 35
  • 5. Guided Practice 9 + 1 + 25 = Any numbers you 9 + 1 = 10 can easily add FIRST to make this easier? 10 + 25 = __
  • 6. Guided Practice 9 + 1 + 25 =
  • 7. Guided Practice 9 + 1 + 25 = Any numbers you can easily add FIRST to make this easier?
  • 8. Guided Practice 9 + 1 + 25 = Any numbers you 9 + 1 = 10 can easily add FIRST to make this easier?
  • 9. Guided Practice 9 + 1 + 25 = Any numbers you 9 + 1 = 10 can easily add FIRST to make this easier? 10 + 25 = __
  • 10. Guided Practice 9 + 1 + 25 = Any numbers you 9 + 1 = 10 can easily add FIRST to make this easier? 35 10 + 25 = __
  • 11. Guided Practice 7 + 13 + 19 =
  • 12. Guided Practice 7 + 13 + 19 = Any numbers you can easily add FIRST to make this easier?
  • 13. Guided Practice 7 + 13 + 19 = Any numbers you 7 + 13 = 20 can easily add FIRST to make this easier?
  • 14. Guided Practice 7 + 13 + 19 = Any numbers you 7 + 13 = 20 can easily add FIRST to make this easier? 20 + 19 = __
  • 15. Guided Practice 7 + 13 + 19 = Any numbers you 7 + 13 = 20 can easily add FIRST to make this easier? 39 20 + 19 = __
  • 16. Guided Practice 29 + 37 =
  • 17. Guided Practice Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away.
  • 18. Guided Practice +1 Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away.
  • 19. Guided Practice +1 -1 Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away.
  • 20. Guided Practice +1 -1 Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away. 30
  • 21. Guided Practice +1 -1 Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away. 30 36
  • 22. Guided Practice +1 -1 Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away. 30 36 30 + 36 = __
  • 23. Guided Practice +1 -1 Remember, this is 29 + 37 = COMPENSATION with adding. ADD something, TAKE something away. 30 36 30 + 36 = 66 __
  • 24. Guided Practice 67 + 14 =
  • 25. Guided Practice Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away.
  • 26. Guided Practice +3 Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away.
  • 27. Guided Practice +3 -3 Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away.
  • 28. Guided Practice +3 -3 Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away. 70
  • 29. Guided Practice +3 -3 Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away. 70 11
  • 30. Guided Practice +3 -3 Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away. 70 11 70 + 11 = __
  • 31. Guided Practice +3 -3 Remember, this is 67 + 14 = COMPENSATION with adding. ADD something, TAKE something away. 70 11 81 70 + 11 = __
  • 32. Guided Practice 38 - 19 =
  • 33. Guided Practice Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers.
  • 34. Guided Practice +2 Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers.
  • 35. Guided Practice +2 +2 Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers.
  • 36. Guided Practice +2 +2 Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers. 40
  • 37. Guided Practice +2 +2 Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers. 40 21
  • 38. Guided Practice +2 +2 Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers. 40 21 40 - 21 = __
  • 39. Guided Practice +2 +2 Remember, this is 38 - 19 = COMPENSATION with subtracting. ADD something to BOTH numbers. 40 21 19 40 - 21 = __
  • 40. Guided Practice 89 - 37 =
  • 41. Guided Practice Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers.
  • 42. Guided Practice -4 Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers.
  • 43. Guided Practice -4 -4 Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers.
  • 44. Guided Practice -4 -4 Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers. 85
  • 45. Guided Practice -4 -4 Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers. 85 33
  • 46. Guided Practice -4 -4 Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers. 85 33 85 - 33 = __
  • 47. Guided Practice -4 -4 Remember, this is 89 - 37 = COMPENSATION with subtracting. ADD something to BOTH numbers. 85 33 85 - 33 = 52 __