Buttons on Sleeves of School Uniforms

Today, I learned the reason why buttons are put on sleeves of school uniforms.

It was occurred when Napoleon's army tried to invade Russia.

Since it was too cold, many soldiers wiped their runny nose using their sleeve.

Napoleon watched them, and angrily said something like "stop doing things like that, it's a shame."

Then he put buttons on sleeves so that they can't wipe their nose.

学生服の袖ボタン

私は今日、学生服の袖にはボタンが付いている理由を知りました。

昔、ナポレオン軍がロシアに攻め入ったときのことです。

あまりに寒く、多くの兵士たちが袖で鼻水を拭いたそうです。

それを見たナポレオンは、「みっともない」と怒りました。

そして、鼻水を拭けないようにボタンをつけました。

• Buttons on Sleeves of School Uniforms
• This sentence is perfect! No correction needed!

• Today, I learned the reason why buttons are put on sleeves of school uniforms.
• This sentence is perfect! No correction needed!

• It was occurred when Napoleon's army tried to invade Russia.
• It whas occurrppened when Napoleon's army tried to invade Russia.

• Since it was too cold, many soldiers wiped their runny nose using their sleeve.
• Since it was too cold, many soldiers wiped their runny noses using their sleeves.

• Then he put buttons on sleeves so that they can't wipe their nose.
• Then he put buttons on their sleeves so that they couldan't wipe their noses.

• It was occurred when Napoleon's army tried to invade Russia.
• It was occurred when Napoleon's army tried to invade Russia.

• Today, I learned the reason why buttons are put on sleeves of school uniforms.
• This sentence is perfect! No correction needed!

• Napoleon watched them, and angrily said something like "stop doing things like that, it's a shame."
• This sentence is perfect! No correction needed!

• It was occurred when Napoleon's army tried to invade Russia.
• It was occurred when Napoleon's army tried to invade Russia.

  You don't need "was" here. To conjugate "occur" in the past, just add an -ed at the end.

• Since it was too cold, many soldiers wiped their runny nose using their sleeve.
• Since it was too*** cold, many soldiers wiped their runny nose using their sleeve.

  Sounds a little weird.
  
  Try "since it was so cold", or "since it was too cold for them to handle"

• Then he put buttons on sleeves so that they can't wipe their nose.
• Then he put buttons on sleeves so that they couldan't wipe their noses.

  Could needs to be used since it is the past tense.
  
  Nose must be plural since you used "they"

• Today, I learned the reason why buttons are put on sleeves of school uniforms.
• Today, I learned the reason why buttons are put on the sleeves of school uniforms.

  Another: Today, I learned the reason behind why buttons are put on the sleeves of school uniforms.

• It was occurred when Napoleon's army tried to invade Russia.
• It began when Napoleon's army tried to invade Russia.

• Since it was too cold, many soldiers wiped their runny nose using their sleeve.
• Since it was so cold, many soldiers wiped their runny noses using their sleeves.

• Napoleon watched them, and angrily said something like "stop doing things like that, it's a shame."
• Napoleon watched them, and angrily said something like "stop doing things like that, it's shameful."

• Then he put buttons on sleeves so that they can't wipe their nose.
• So he put buttons on sleeves so that they couldn't wipe their nose.

  I've left out "their" because he put buttons on all sleeves, not just their sleeves in particular.

I've always wondered about those buttons too. Pretty funny haha

• Buttons on Sleeves of School Uniforms
• Buttons on Sleeves of School Uniforms

  It could also be said 'Buttons on the Sleeves of School Uniforms'

• Today, I learned the reason why buttons are put on sleeves of school uniforms.
• Today, I learnedt the reason why buttons are put on sleeves of school uniforms.

  Learned is an english word, learnt is more accurate for this context though.

• It was occurred when Napoleon's army tried to invade Russia.
• It begwans to be commonplacurred aftwhern Napoleon's army tried to invade Russia.

  Better wording

• Since it was too cold, many soldiers wiped their runny nose using their sleeve.
• Since it was tsoo cold, many soldiers wiped their runny nose usi ong their sleeve.

  Simple contextual errors.

• Napoleon watched them, and angrily said something like "stop doing things like that, it's a shame."
• Napoleon watched them, and angrily said something like "stop doing things like that, it's a shameful."

  Grammatical errors

• Then he put buttons on sleeves so that they can't wipe their nose.
• Then he put buttons on sleeves so that they couldan't wipe their nose with it.

  Wrong tense for 'cant' and added context

Good luck with your assignment :)