12
$18 × 9 =$
$100 ÷ 50 =$
$100 - 72 =$
$900 ÷ 60 =$
$78 + 19 =$
$79 × 5 =$
$560 ÷ 40 =$
$74 - 59 =$
$56 + 16 =$
$490 × 20 =$
$700 ÷ 5 =$
$64 × 4 =$
$70 - 12 =$
$25 × 8 =$
$910 ÷ 70 =$
$13 + 87 =$
$19 × 40 =$
$64 - 49 =$
$85 + 18 =$

1. $18×9 = 162$
2. $100÷50 = 2$
3. $100 - 72 = 28$
4. $900÷60 = 15$
5. $78 + 19 = 97$
6. $79×5 = 395$
7. $560÷40 = 14$
8. $74 - 59 = 15$
9. $56 + 16 = 72$
10. $490×20 = 9800$
11. $700÷5 = 140$
12. $64×4 = 256$
13. $70 - 12 = 58$
14. $25×8 = 200$
15. $910÷70 = 13$
16. $13 + 87 = 100$
17. $19×40 = 760$
18. $64 - 49 = 15$
19. $85 + 18 = 103$

用简便方法计算
$(80 + 8) × 125$ $7 × 125 + 125$
$48 × 102$ $125 × 56$
$46 × 9 + 54 × 9$ $278 + 296 + 22$
$25 × (17 × 4)$ $44 × 25$
$125 × 32$ $7 × 25 × 4 × 8$

1.$(80 + 8)× 125$
$=80× 125 + 8× 125$
$=10000 + 1000$
$=11000$
2.$7× 125 + 125$
$=(7 + 1)× 125$
$=8× 125$
$=1000$
3.$48× 102$
$=48×(100 + 2)$
$=48× 100+48× 2$
$=4800 + 96$
$=4896$
4.$125× 56$
$=125× 8× 7$
$=1000× 7$
$=7000$
5.$46× 9 + 54× 9$
$=(46 + 54)× 9$
$=100× 9$
$=900$
6.$278 + 296 + 22$
$=(278 + 22)+296$
$=300+296$
$=596$
7.$25×(17× 4)$
$=25× 4× 17$
$=100× 17$
$=1700$
8.$44× 25$
$=(40 + 4)× 25$
$=40× 25+4× 25$
$=1000 + 100$
$=1100$
9.$125× 32$
$=125× 8× 4$
$=1000× 4$
$=4000$
10.$7× 25× 4× 8$
$=(25× 4)×(7× 8)$
$=100× 56$
$=5600$