①17.8-8.75+2.2-1.25,
=(17.8+2.2)-(8.75+1.25),
=20-10,
=10;
②0.125×32×2.5,
=(0.125×8)×(4×2.5),
=1×10,
=10;
③
4
7 +
7
8 +
3
7 +
1
8 ,
=(
4
7 +
3
7 )+(
7
8 +
1
8 ),
=1+1,
=2;
④
4
7 +(
17
24 -
4
7 ),
=
4
7 -
4
7 +
17
24 ,
=
17
24 .
①17.8-8.75+2.2-1.25,
=(17.8+2.2)-(8.75+1.25),
=20-10,
=10;
②0.125×32×2.5,
=(0.125×8)×(4×2.5),
=1×10,
=10;
③
4
7 +
7
8 +
3
7 +
1
8 ,
=(
4
7 +
3
7 )+(
7
8 +
1
8 ),
=1+1,
=2;
④
4
7 +(
17
24 -
4
7 ),
=
4
7 -
4
7 +
17
24 ,
=
17
24 .