1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+19+20/20
Tính nhẩm:
| 16 − 8 = ..... | 14 − 7 = ..... | 18 − 9 = ..... |
| 9 + 8 = ..... | 7 + 6 = ..... | 5 + 7 = ..... |
| 12 − 6 = ..... | 4 + 7 = ..... | 17 − 9 = ..... |
| 20 − 1 = ..... | 20 − 5 = ..... | 20 − 10 = ..... |
Tính nhẩm:
| 2 × 8 = ... | 16 : 2 = ... |
| 21 : 3 = ... | 4 × 5 = ... |
| 3 × 8 = ... | 24 : 3 = ... |
| 5 × 6 = ... | 5 × 4 = ... |
| 4 × 8 = ... | 40 : 4 = ... |
| 28 : 4 = ... | 20 : 4 = ... |
| 5 × 8 = ... | 40 : 5 = ... |
| 3 × 6 = ... | 20 : 5 = ... |
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20=
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20=
Tính:
30 + 16 − 37 = ...... = .......
5 × 7 + 35 = ...... = .......
20 : 4 × 6 = ...... = .......
40 : 5 : 2 = ...... = .......
Đố mọi người : 1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20 = ?
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26
| 2 × 8 = ... | 16 : 2 = ... |
| 21 : 3 = ... | 4 × 5 = ... |
| 3 × 8 = ... | 24 : 3 = ... |
| 5 × 6 = ... | 5 × 4 = ... |
| 4 × 8 = ... | 40 : 4 = ... |
| 28 : 4 = ... | 20 : 4 = ... |
| 5 × 8 = ... | 40 : 5 = |