| 6 |
| 13 |
| 7 |
| 13 |
| 17 |
| 10 |
(2)1998÷1998
| 1998 |
| 1999 |
(3)6.8×
| 8 |
| 25 |
(4)
| 1 |
| 2×4 |
| 1 |
| 4×6 |
| 1 |
| 6×8 |
| 1 |
| 48×50 |
| 6 |
| 13 |
| 7 |
| 13 |
| 17 |
| 10 |
=(
| 6 |
| 13 |
| 7 |
| 13 |
| 17 |
| 10 |
=1×1.7÷
| 17 |
| 10 |
=1.7÷
| 17 |
| 10 |
=1;
(2)1998÷1998
| 1998 |
| 1999 |
=1998÷
| 1998×1999+1998 |
| 1999 |
=1998÷
| 1998×(1999+1) |
| 1999 |
=1998÷
| 1998×2000 |
| 1999 |
=1998×
| 1999 |
| 1998×2000 |
=
| 1999 |
| 2000 |
(3)6.8×
| 8 |
| 25 |
=6.8×0.32+0.32×4.2-0.32,
=(6.8+4.2-1)×0.32,
=10×0.32,
=3.2;
(4)
| 1 |
| 2×4 |
| 1 |
| 4×6 |
| 1 |
| 6×8 |
| 1 |
| 48×50 |
=
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 6 |
| 1 |
| 8 |
| 1 |
| 48 |
| 1 |
| 50 |
=
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 50 |
=
| 1 |
| 2 |
| 12 |
| 25 |
=
| 6 |
| 25 |