×=(2×)×(4×)=(2×4)×(×)
×=(4×)×(5×)=(×)×(×)
×9= ×0= ×= ×17=
×100= += ×= ×=
① × ×
② × ×
③ × ×
④20× ×
⑤ × ×
⑥ ×14×