Common Core Math is Not the Enemy
Brett Berry
3.6K166

A GOOD teacher will teach the concepts in a more concrete way BEFORE the algorithm is shown as a SHORTCUT. In the case of the problem shown, one might start with using monopoly money and whenever a “group of ten” (be it ten ones or ten tens), it’s time to “cash in” for a bigger denomination bill.

In my book (which is similar to what is taught in Singapore (which is said to have one of the best math programs in the world), start with boxes of crayons/pencils and boxes of boxes for the place values.

http://www.lulu.com/shop/steven-holmes/learning-algebra-through-graphing/paperback/product-20634128.html