YOU SAID:

the speed of light is about three hundred million meters per second

INTO JAPANESE

光の速度は毎秒約 3 億メートルです。

BACK INTO ENGLISH

The speed of light is 300 million metres per second.

INTO JAPANESE

光の速度は秒速 3 億の m です。

BACK INTO ENGLISH

The speed of light is 300 million/s m.

INTO JAPANESE

光の速度は、3 億/s m です。

BACK INTO ENGLISH

The speed of light is 300 million m/s.

INTO JAPANESE

光の速度は 300 百万 m/s。

BACK INTO ENGLISH

The speed of light is 300 million m / s.

INTO JAPANESE

光の速度は 3 億 m/s。

BACK INTO ENGLISH

The speed of light is 300 million m / s.