1. Math 801A: Mathematical Operations – Decimal Fractions
Mathematics Essentials
March 2nd, 2017

2. Lesson Introduction Today I will...
use mental math and estimation strategies for operations involving integers and decimal fractions
apply mental math and estimation strategies in problem situations when appropriate
perform operations involving integers and decimal fractions in practice and problem situations using the most appropriate method

3. Decimal Fractions
In the “real world”, you wont always be able to work with whole number
You may need to work with parts of a whole such as decimalas
Particularly when a specific level of precision is required

4. Adding/Subtracting Decimal Fractions
place values
perform operation
add decimal
Step 1 – write the two numbers being added/subtracted with their decimal points aligned (zeros can always be included to represent place value).
Step 2 – add/subtract the numbers as you would with whole numbers.
Step 3 – place the decimal in the answer such that it is aligned with numbers being added/subtracted.

5. Practice
Solve 1 A, C, D, F using:
Estimation
Pencil and paper

6. Multiplying Decimal Fractions
Performed in a similar way to mutipling whole numbers
Difference occurs in writing the resulting answer
**When multiplying numbers containing decimals, the answer must contain the same number of decimal places as the sum of the decimal places in the two numbers being multiplied.

7. Practice
Solve 3 A, B, C using:
Estimation
Pencil and paper

8. Dividing Decimal Fractions
Performed in a similar way to dividing whole numbers
Difference occurs in writing the resulting answer
**When dividing numbers containing decimals by a whole number, the decimal point in the answer must align with the decimal in the number being divided

9. Practice
Solve 3 D, E, F using:
Estimation
Pencil and paper

10. Homework!
For tomorrow (Friday’s class):
Pg 20, q’s 5-8
Pg 21, q’s 1+2