THE BIG IDEA
This objective connects slope and dilation together. I think the big idea here is simply using skills to solve problems using coordinates and coordinate skills.
TRAPS & PITFALLS
For the most part this isn't too difficult as long as they remember the things covered earlier in the year with dilations. The only real issue is to alter ratios from piece comparison (1:3) to scale factor (1/4). Dilation is based on amount of the whole whereas most ratios are provided comparing to each other.
PAST CONNECTIONS
The student needs to use a reduction dilation to be able to perform this objective which is an earlier objective. The concept of slope is also a very important foundational understanding here.
FUTURE CONNECTIONS
Ultimately this is about ratios and coordinates which do show up in different shapes and problems later on. This also bridges a student from 'directed line segments' to VECTORS.
MY REFLECTIONS (over line l )
I think I should just teach this right after dilations in unit #2. Students will still remember the connection between slope and dilation and then the only thing that they are adding is converting ratios to scale factors. While this does deal with coordinates and is included in this unit I think it fits best in unit #2.
