读口诀，写算式。二三得六□×□=□□×□=□二七十四□×□=□□×□=□二九十八□×□=□□×□=□二四得八□×□=□□×□=□二五一十□×□=□□×□=□二六十二□×□=□□×□=□二八十六□×□=□□×□=□二二得四□×□=□