Estimate the results of the following(each number correct to the nearest integer)
1a) 1.29+5.78+0.96+2.12(rounding off)
1b) 5.92x31(rounding down)
1c)2.16+3.721.83+4.32(rounding up)
1d)28x4.21(rounding off)
Estimate the results of the following by front-end method
2a)2.12+6.65+1.97+3.38+1.83
2b)1326+4158+668+3824
2c)4.68+0.98+1.21+2.36+3.82
2d)228+347+158+73
ps.要有steps
唔該~~