8÷10= 9÷6= 18÷20= 9÷8=
15÷16= 21÷14= 56÷16= 9÷54=
=
0.3²=
+=
-=
-2=
① - +
②1+1.9+2.9+3.9+4.9+5.9
③ - + -
④ -( + )-
⑤5- +
⑥2.8×0.5+5×2.72
① + ×
② ÷ ×
③( + + )×18
④7.5× +7.5×
⑤ -( - )
⑥ -( + )