28+21×3
5(54-24)-18÷15
243
-14÷21
解説動画 ≫
57
4530
63
28+21×3
=27+37
=57
5(54-24)-18÷15
=5(36-26)-1815
=5×6-65
=30-305
=4530
243
-14÷21
=236- 1421
=236- 23
=236- 136
= 63