This unit I found to be very beneficial. It focused mostly on all the different ways there are to add, subtract, and estimate. I really enjoyed this unit because I believe there are always multiple ways to teach something new and it is up to the individual to find out what method works best for him/her. After this unit I was able to see what methods worked best for me.
One new method of adding that I had never heard of before was lattice adding. It is complicated to explain, so you can play the video below to find out more about it. I think lattice multiplication will be a method I teach to my students.
Estimation was also a huge part of our homework this chapter and it is definitely something that has been left in the dark. More and more kids today I'm finding, are having a hard time when it comes to making a close guess or estimation of something. I especially notice it when it comes to measuring. Estimating to help add and subtract however is mostly what we focused on and it definitely helped to save time when solving problems. I found front end estimating to be the easiest and below is a link that helped me figure out how to do it.