4A 沪教版数学专项复习递等式计算、能巧算的巧算
:___________日期:__________开场时间:_________完成时间:_________
1. | 4×19×25×7 | 2. | 172+583-283+628 |
| | | |
| | | |
| | | |
| | | |
3. | 285×〔25+25+25+25〕 | 4. | 779+536+221+4 |
| | | |
| | | |
| | | |
| | | |
5. | 803-123-377 | 6. | 36×15÷36×15 |
| | | |
| | | |
| | | |
| | | |
7. | 25××125 | 8. | 7200÷36÷2 |
| | | |
| | | |
| | | |
| | | |
9. | 125×〔6×8〕×50 | 10. | 9000÷125÷8 |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
11. | 125×34×8 | 12. | 300-225÷5+145 |
| | | |
| | | |
| | | |
| | | |
13. | 3500-175-925 | 14. | 6300÷〔63×5〕 |
| | | |
| | | |
| | | |
| | | |
15. | 355+260+140+245 | 16. | 32×25×125 |
| | | |
| | | |
| | | |
| | | |
17. | 425-38+75-162 | 18. | 136×101-136 |
| | | |
| | | |
| | | |
| | | |
19. | 126+95+74+805 | 20. | 8×35+8×90 |
| | | |
| | | |
| | | |
| | | |
21. | 630×24÷70÷12 | 22. | 639-148-252+261 |
| | | |
| | | |
| | | |
23. | 〔408×4〕÷〔408×2〕 | 24. | 79×42+79+79×56 |
| | | |
| | | |
| | | |
| | | |
25. | 455+999×999+545 | 26. | 7300÷25÷4 |
| | | |
| | | |
| | | |
| | | |
27. | 〔13×125〕×〔3×8〕 | 28. | 178×101-178 |
| | | |
| | | |
| | | |
| | | |
29. | 84×36+×84 | 30. | 75×99+2×75 |
| | | |
| | | |
| | | |
| | | |
31. | 763+276+724 | 32. | 125×24 |
| | | |
| | | |
| | | |
| | | |
33. | 872-〔12×30-28〕 | 34. | 26×74+74×74 |
| | | |
| | | |
| | | |
35. | 25×16×21 | 36. | 〔40+1〕×25 |
| | | |
| | | |
| | | |
| | | |
37. | 137×46-46×37 | | |
| | | |
| | | |
| | | |
| | | |
4A 沪教版数学专项复习递等式计算、能巧算的巧算参
:___________日期:__________开场时间:_________完成时间:_________
1. | 4×19×25×7 | 2. | 172+583-283+628 |
| =4×25×19×7 | | =172+628+583-283 |
| =〔4×25〕×〔19×7〕 | | =〔172+628〕+〔583-283〕 |
| =100×133 | | =800+300 |
| =13300 | | =1100 |
3. | 285×〔25+25+25+25〕 | 4. | 779+536+221+4 |
| =285×〔25×4〕 | | =779+221+536+4 |
| =285×100 | | =〔779+221〕+〔536+4〕 |
| =28500 | | =1000+1000 |
| | | =2000 |
5. | 803-123-377 | 6. | 36×15÷36×15 |
| =803-〔123+377〕 | | =36÷36×15×15 |
| =803-500 | | =〔36÷36〕×〔15×15〕 |
| =303 | | =1×225 |
| | | =225 |
7. | 25××125 | 8. | 7200÷36÷2 |
| =25×4×125×8×2 | | =7200÷〔36×2〕 |
| =〔25×4〕×〔125×8〕×2 | | =7200÷72 |
| =100×1000×2 | | =100 |
| =200000 | | |
9. | 125×〔6×8〕×50 | 10. | 9000÷125÷8 |
| =125×6×8×50 | | =9000÷〔125×8〕 |
| =125×8×6×50 | | =9000÷1000 |
| =〔125×8〕×〔6×50〕 | | =9 |
| =1000×300 | | |
| =300000 | | |
| | | |
11. | 125×34×8 | 12. | 300-225÷5+145 |
| =125×8×34 | | =300-45+145 |
| =〔125×8〕×34 | | =300+145-45 |
| =1000×34 | | =300+〔145-45〕 |
| =34000 | | =300+100 |
| | | =400 |
13. | 3500-175-925 | 14. | 6300÷〔63×5〕 |
| =3500-〔175+925〕 | | =6300÷63÷5 |
| =3500-1100 | | =〔6300÷63〕÷5 |
| =2400 | | =100÷5 |
| | | =20 |
15. | 355+260+140+245 | 16. | 32×25×125 |
| =355+245+260+140 | | =4×25×8×125 |
| =〔355+245〕+〔260+140〕 | | =〔4×25〕×〔8×125〕 |
| =600+400 | | =100×1000 |
| =1000 | | =100000 |
17. | 425-38+75-162 | 18. | 136×101-136 |
| =425+75-38-162 | | =136×101-136×1 |
| =〔425+75〕-〔38+162〕 | | =136×〔101-1〕 |
| =500-200 | | =136×100 |
| =300 | | =13600 |
19. | 126+95+74+805 | 20. | 8×35+8×90 |
| =126+74+95+805 | | =8×〔35+90〕 |
| =〔126+74〕+〔95+805〕 | | =8×125 |
| =200+900 | | =1000 |
| =1100 | | |
21. | 630×24÷70÷12 | 22. | 639-148-252+261 |
| =630÷70×24÷12 | | =639+261-148-252 |
| =〔630÷70〕×〔24÷12〕 | | =〔639+261〕-〔148+252〕 |
| =9×2 | | =900-400 |
| =18 | | =500 |
23. | 〔408×4〕÷〔408×2〕 | 24. | 79×42+79+79×56 |
| =408×4÷408÷2 | | =79×42+79×1+79×56 |
| =408÷408×4÷2 | | =79×〔42+1+56〕 |
| =〔408÷408〕×〔4÷2〕 | | =79×99 |
| =1×2 | | =79×〔100-1〕 |
| | | =79×100-79×1 |
| | | =7900-79 |
| | | =7821 |
| =2 | |
25. | 455+999×999+545 | 26. | 7300÷25÷4 |
| =455+545+999×999 | | =7300÷〔25×4〕 |
| =999+999×999 | | =7300÷100 |
| =999×1+999×999 | | =73 |
| =999×〔1+999〕 | | |
| =999×1000 | | |
| =999000 | | |
27. | 〔13×125〕×〔3×8〕 | 28. | 178×101-178 |
| =13×125×3×8 | | =178×101-178×1 |
| =125×8×13×3 | | =178×〔101-1〕 |
| =〔125×8〕×〔13×3〕 | | =178×100 |
| =1000×39 | | =17800 |
| =39000 | | |
29. | 84×36+×84 | 30. | 75×99+2×75 |
| =84×〔36+〕 | | =75×〔99+2〕 |
| =84×100 | | =75×101 |
| =8400 | | =75×〔100+1〕 |
| | | =75×100+75×1 |
| | | =7500+75 |
| | | =7575 |
31. | 763+276+724 | 32. | 125×24 |
| =763+〔276+724〕 | | =125×8×3 |
| =763+1000 | | =〔125×8〕×3 |
| =1763 | | =1000×3 |
| | | =3000 |
33. | 872-〔12×30-28〕 | 34. | 26×74+74×74 |
| =872-〔360-28〕 | | =74×〔26+74〕 |
| =872-360+28 | | =74×100 |
| =872+28-360 | | =7400 |
| =900-360 | | |
| =540 | | |
35. | 25×16×21 | 36. | 〔40+1〕×25 |
| =25×4×4×21 | | =40×25+1×25 |
| =〔25×4〕×〔4×21〕 | | =1000+25 |
| =100×84 | | =1025 |
| =8400 | | |
37. | 137×46-46×37 | | |
| =46×〔137-37〕 | | |
| =46×100 | | |
| =4600 | | |
| | | |
巧算的核心:凑整。〔整十、整百、整千〕
20×5=100、25×4=100、125×8=1000。
必须在巧算题型中熟练掌握并应用:加法交换律、加法结合律、乘法交换律、乘法结合律、乘法分配律。