Use mental math strategies to solve the following problems in your head. Record the strategy that you used for each problem and the answer.
The Lesson 3.1.2 Math Notes box describes three useful strategies. Try using ''Pulling Apart'' for this one.
You could think of
as and as .
You can rearrange the parts so that this sum is
? Can you adjust this for ?
Try using ''Give and Take'' for this one!