Làm toán bằng cách “múa” ngón tay
(TNO) - Chỉ với chiếc bàn tính hạt gỗ treo trên bảng, các bé ngồi dưới lớp học thực hiện động tác “múa” ngón tay, tưởng tượng sắp xếp các hạt gỗ để tính được những phép toán trong thời gian ngắn.
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