问题 填空题 数一数，算一算，并改错。1. － = six _____________2. + = thirteen _____________3. + = nineteen _____________4. + = four _____________ 答案 1. five 2. fifteen 3. nine 4. fourteen
－ 
= six _____________
+ 
= thirteen _____________
+ 
= nineteen _____________
+ 
= four _____________
