a) 98 x 31 + 62
= 31 x ( 98 + 2 )
=31 x 100
= 3100
b) 635 x 2 =1270
c) 375 x 4 =1500
a) \(98.31+62=98.31+31.2=31.\left(98+1\right)=31.100=3100\)
b) \(635.2=1270\)
c) \(375.4=1500\)
a) 98 x 31 + 62 = 3038 + 62
= 3100 .
b) 635 x 2 = 1270 .
c) 375 x 4 = 1500 .