①503+197= ② ×15= ③0.8+ = ④3.6×25%=
⑤ + × = ⑥ ÷ = ⑦8.01-2.1= ⑧ × =
⑨47.8÷5.9≈ ⑩12.5×8÷12.5×8=
1624÷56= 4.5×5.02= 13.05-3.96=
3.15÷15= 1- + =