5-0.8= 0.57+1.3= 1.8×0.1= 3.4-2.6=
16.8÷100= 22.6×10= 2×4.5= 4.99×3.01≈
①1.75÷0.25×0.4
②3.6×101-3.6
③7.2÷1.6+1.8
④7.24×0.1+0.5×72.4+0.049×724
⑤99.66×6+66.78×18