Adding and subtracting decimals  Decimals
Adding and subtracting decimals
In this section, we will add and subtract decimal numbers. The process of adding and subtracting decimal numbers is the same as adding and subtracting whole numbers. For example, both involve regrouping. After lining up the decimals, you will sometimes have to add one or more zeroes to a number after the decimal point. Being able to add and subtract decimal numbers is an important life skill, especially when dealing with money and purchases.
Basic concepts:
 Divisibility rules
 Prime factorization
 Introduction to Exponents
Related concepts:
 Percents, fractions, and decimals
Lessons

a)
i) How to add decimals?
ii) How to subtract decimals? 
b)
How to round decimals?


1.
Evaluate. Then, round your answer to the nearest tenth.

2.
The table shows the approximate lengths of some dinosaurs.
Dinosaur
Height
Dryosaurus
6.52ft
Chasmosaurus
6.2ft
Ankylosaurus
7.22ft
Dravidosaurus
4.1ft