(1)931四÷23+77,
=40四+77,
=482;
(2)7.38-(1.四7+2.38),
=7.38-1.四7-2.38,
=7.38-2.38-1.四7,
=四-1.四7,
=3.43;
(3)
9
10 +
9
10 ×99,
=
9
10 ×(99+1),
=
9
10 ×100,
=90;
(4)
3
四 ÷[(
1
四 +
1
3 )÷
2
9 ],
=
3
四 ÷[
8
1四 ×
9
2 ],
=
3
四 ÷
12
四 ,
=
1
4 .
(1)931四÷23+77,
=40四+77,
=482;
(2)7.38-(1.四7+2.38),
=7.38-1.四7-2.38,
=7.38-2.38-1.四7,
=四-1.四7,
=3.43;
(3)
9
10 +
9
10 ×99,
=
9
10 ×(99+1),
=
9
10 ×100,
=90;
(4)
3
四 ÷[(
1
四 +
1
3 )÷
2
9 ],
=
3
四 ÷[
8
1四 ×
9
2 ],
=
3
四 ÷
12
四 ,
=
1
4 .