| 摘要 |
<p>#CMT# #/CMT# The board has a planar surface on which lines of numbers are registered. The numbers are natural numbers including zero and are ordered sequentially. The number 1 is repeated twice and follows zero such that the first 1 represents a unit and the second 1 represents a set of 8,10,12 or 16. A mobile object in each line slides above the numbers while keeping the numbers visible. The numbers are chosen from each line to perform addition or multiplication. #CMT#USE : #/CMT# For use in addition and multiplication.</p> |
