=37×(9 1+8+ 1)
=37× 100
=3700
9 1+67×9 1+32×9 1
=9 1×( 1+67+32)
=9 1× 100
=9 100
50×(? +4)
=50×? +50× 4 ... According to the law of multiplication and distribution.
=50×? +200
50×? +4,
Observing the above two formulas, it is found that it is also "50×? Just compare "200" and "4".
Difference: 200-4 = 196