Partial Sums

Front End Estimation

Rounding

Here is a simple explanation with whole numbers.

Rounding Decimals

Adding Decimals using a Decimal Square

Adding Decimals Using Decimal Models

Subtracting Decimals with Decimal Models

*Please note that in the video there is an error at the very end. Mrs. Kewriga accidentally says 5 hundredths, rather than 5 tenths. The 5 in the answer is in the tenths place.

Rounding and Estimating Decimal Addition and Subtraction