7878÷78=
5656÷56=
567567÷567=
28×730+73×720
24×56+48×22
36×98+72
999×778+ 333×666
800÷25×4 99×72 831-243-457+169
7200÷(72×5) 48×56+54×56-56×2 999×999+1999
①1.25×3.2×2.5
②×[0.75﹣()]
③×()
④2022×
⑤55×102+646÷38