92+99 197+102 354-108
=92+(100-1) =197+(100+2) =354-(100+8)
=92+100-1 =197+100+2 =354-100-8
=191 =299 =246
405-99 127-98 323+189-123
=405-(100-1) =127-(100-2) =323-123+189
= 405-100+1 =127-100+2 =389
=306 =29
545-167-145 478-47-178 344-(144+37)
=545-145-167 =478-178-47 =344-144-37
=233 =253 =163
236-(177+36) 400-256-44 517-53-47
=236-36-177 =400-(256+44) =517-(53+47)
=23 =100 =417
248+86-48 672-36+64 (6467-832)+(1832-1467)
=248-48+86 =672-(36+64) =6467-1467+(1832-832)
= 286 =572 =6000
1530+(592-530)-192 (2+4+6+……+98+100)-(1+3+5+……+97+99)
=1530-530+(592-192) =(2-1)+(4-3)+…+(98-97)+(100-99)
=1400 =1+1+...+1+1 =50
25×9×4 45×4×5 23 ×5×2
=25×4×9 =45×(4×5) =23×(5×2)
=900 =90 =230
8×(125×13) (250×125)×(4×8)
=8×125×13 =125×8×(250×4)
=13000 =1000000
42×125×8×5 25×4×88×125
=125×8×(42×5) =100×11×(8×125)
=210000 =1100000
72×125 125×64×25 42×125×8×5
=8×125×9 =125×8×(25×8) =42×5×(125×8)
=9000 =200000 = 210000
25×4×88×125 88×125
=100×(8×125) ×11 =8×125×11
=100×1000×11 =1000×11
=100000×11 =11000
=1100000