Estimate each product using rounding or compatible numbers: 4.05 x 11

Estimate each product using rounding or compatible numbers: 0.83 x 12
Estimate each product using rounding or compatible numbers: 0.89 x 51
Estimate each product using rounding or compatible numbers: 99.3 x 92
Estimate each product using rounding or compatible numbers: 47.2 x 93