Choose a Method……. Any Method
By: Teresa Henderson
NC Competency and Objectives:
• 1.06 Develop flexibility in solving
problems by selecting strategies and using mental computation, estimation, calculators or computers, and paper and pencil
multi-digit addition and subtraction through 9,999
• 1.02 (a,b,c) Develop fluency with
Review Time!
•SUM •DIFFERENCE •DIGIT •ESTIMATE
Check yourself
• Sum – The answer
when you add.
• Estimate – Find an
answer that is close to the exact answer.
• Difference – The
• Digit – A number.
answer when you subtract.
(Example in the number 234 the symbol 2 is called a digit.)
What is Mental Math?
Mental Math -means doing
mathematics in your MIND---in your head, without using paper and pencil.
Use your MIND to solve the problems.
Practice Makes
Perfect!
4. 674 5.
1. 2.
786+656=? 837+123=?
– 234=?
985 – 134=?
3.
983+325=?
6.
770 – 238=?
Use Paper and Pencil to solve the problems.
Practice Makes
Perfect!
4. 674 5.
1. 2.
786+656=? 837+123=?
– 234=?
985 – 134=?
3.
983+325=?
6.
770 – 238=?
Use a Calculator to solve the problems.
Practice Makes
Perfect!
4. 674 5.
1. 2.
786+656=? 837+123=?
– 234=?
985 – 134=?
3.
983+325=?
6.
770 – 238=?
Mentally Estimate: Round each number to the greatest place.
Practice Makes
Perfect!
4. 674 5.
1. 2.
786+656=? 837+123=?
– 234=?
985 – 134=?
3.
983+325=?
6.
770 – 238=?
Use a Computer to solve the problems.
Practice Makes
Perfect!
4. 674 5.
1. 2.
786+656=? 837+123=?
– 234=?
985 – 134=?
3.
983+325=?
6.
770 – 238=?
Do you have any questions?