chia số có 2 chữ số với số có 1
chữ số
86:9=...........................................................................................................................................................................
65:7=...........................................................................................................................................................................
43:5=..........................................................................................................................................................................
86:7=..........................................................................................................................................................................
65:5=..........................................................................................................................................................................
43:3=..........................................................................................................................................................................
76:7=...........................................................................................................................................................................
87:6=...........................................................................................................................................................................
65:5=..........................................................................................................................................................................
579 x 86 - 527 x 76
= 579 x ( 10 + 76 ) - 527 x 76
= 579 x 10 + 579 x 76 - 527 x 76
= 5790 + ( 579 - 527 ) x 76
= 5790 + 52 x 76
= 5790 + 3952
= 9742