Here is yet another example of Common Core assignments making simple math more “accessible.”
— Kim (@JBaileysMom) March 22, 2014
There are many problems with this. While it is a convenient “trick” and shortcut method of adding two numbers, not everyone will use the same trick. For example, the “Think 17 = 13 + 4″ might be better stated as Think 17 – 4 = 13.” but the problem is that it is just a mental shortcut.
Children need to understand how to do mathematics rigorously. While with simple problems this isn’t a big deal, the understanding of how to do it in a rigorous manner is necessary for more complected problems to be done correctly.
The main problem is that this is just teaching shortcuts that are difficult if not impossible to translate into broader more general principles. Rather than using rigorous methods to establish building blocks to higher and more complex mathematics, it provides an easy way out that leaves the student unprepared for more complex problems.
With that above Common Core method, it the lesson becomes not about adding to numbers together, but of going through the motions without emphasizing the basics. ‘Tis too clever by half.