1加到50等于多少
2025-10-08
1加到50这道题运用凑十法如1+9=10; 2+8=10; 4+6=10,11+19=30,12+18=30,13+17=30,14+16=30; 21+29=50; 23+27=50; 24+26=50; 31+39=70...
2025-10-08
1加到50这道题运用凑十法如1+9=10; 2+8=10; 4+6=10,11+19=30,12+18=30,13+17=30,14+16=30; 21+29=50; 23+27=50; 24+26=50; 31+39=70...