We learned that we can use the same strategies and algorithms for adding and subtracting whole numbers to add and subtract decimals.

We learned that it is helpful to estimate a sum before calculating it. For example, this sum will be close to or 690.

We learned to align the place values when adding and subtracting.

Subtract. 6 hundred 22 and 35 hundredths, minus, 71 and 40 hundredths, equals, 5 hundred 50 and 95 hundredths.

We estimated that the value of the difference will be about or 550.