To the outsiders of the USA, we can understand the “Common Core Math Program” is good for American children education, which is supported by Bill Gates with generous $6-billion donation.
The American parents who resist and oppose the ‘Common Core’ Math are like the Singaporean parents who opposed the “Singapore Math Program” in the 1980s. The Singaporean parents had to go through remedial classes before they could coach their kids in the ‘new way’. Result proved that after 20 years, Singapore is ranked 2nd in the PISA Test World Ranking in Math (after Shanghai of China).
All good medicines are bitter to swallow. 良药苦口 !
Here are 4 methods of subtraction:
1st : Traditional (aka Abacus) “Carry” Method
2nd: Mental Calculation
3rd : “Singapore Math” (no Carry)
4th: Common Core: “Count Up” (French Method), with which French supermart cashiers usually perform changes at counter — much slower than the 1st one (Traditional Method).
The French method looks stupid in practical, but it teaches the kids the essence of Math from simple arithmetic – Math is not calculation but the “Nature of Things”, Math is not just memorized algorithm like a robot. It goes a long way later when French kids grow up to grasp more rigorous advanced Math concepts like Groups, Rings, Fields, Vector Spaces… it is no wonder France is the Math “Super-Power” alone winning 1/3 of Fields Medals (Nobel Prize equivalent in Math).
It is a change of mindset and old habit of doing things, which makes parents feel uncomfortable.
Think about it… Ask 90% of adults today who had learnt Math in the traditional method:
9 – 5 × 2 + 8 ÷ 2 = ?
[Answer = 9 – (5 × 2) + (8÷ 2) = 3]
“Why perform (x, ÷) before (+, – )?”
Similarly, imagine a 8 or 9 year-old kid would ask in their little head,
“What the heck is ‘carrying 1’ or ‘borrowing 1’ means actually ?”
Here are Grade 4 “Common Core” Multiplication & Division :