(7歲4個月,一年級下)Chapter 5 How our “ten” system works and the invention of nothing
這一章主要講了阿拉伯數(shù)字的位值,介紹了算盤,以及零的出現(xiàn)。一年級下的小盆友已經在學校里學過算盤了。對算盤的了解有助于對內容的理解。
書里反復強調的是,Each position is worth ten times more than the one on its right. Just like written numbers,each wire on the abacus is worth ten times more than the wire on its right.