Adding and Subtracting Decimals

Topics for Today:

We are getting back into the swing of things, and setting up classroom routines.  Today we did a bit of review of adding and subtracting decimals.

**Adding/Subtracting Decimal Numbers MAIN IDEA***
--> When adding or subtracting decimals, always line up the decimal points!

We also did a brief review of subtracting decimals using regrouping, as well as bringing in zeroes (called annexing) to make sure our numbers line up.   We also discussed a few of the properties of equality.

Vocabulary:

identity property of addition, commutative property of addition, associative property of addition

Sections Covered in Textbook:

1-2: Adding and Subtracting Decimals (pages 11-15)

Resources & Tutorials:

1) How do you add decimals?
2) How do you subtract decimals?

3) 1-2 Adding and Subtracting Decimals Class Notes

Extras:

Find those numbers!

Estimation Strategies

Topics for Today:

Today we discussed some strategies for estimating the answers to numeric expressions.  Students were asked to consider both how to estimate as well as the reasons why we use estimation.  We will spend a lot of discussion time this school year on number sense, and determining if our solutions to problems make sense. 

Image Credit: https://www.slideshare.net/Ms.DH/31-rounding-and-estimating-presentation

Vocabulary:

estimate, compatible numbers, sum, difference, product, quotient

Sections Covered in Textbook:

1-1: Using Estimation Strategies (pages 5 - 9)

Resources & Tutorials:

1)  How do you use front-end estimation to estimate a sum of several decimals?
2)  How do you estimate a quotient using compatible numbers?

Extras:
1) Guess It!  - Online Estimation Game