So, people actually walked along the coastlines and measured distances to make maps. A tad more formal: Therefore, people were required to walk the coastlines and take measurements in order to make maps. So, people actually walked along the coastlines and measured distances to make maps. A tad more formal: Therefore, people were required to walk the coastlines and take measurements in order to make maps.

He was curious about how the stars and the sun worked, and how big the Earth was. He was curious about the workings of the stars and sun and how big the Earth was. Very nice use of indirect question here! Even native speakers mess that up. He was curious about how the stars and the sun worked, and how big the Earth was. He was curious about the workings of the stars and sun and how big the Earth was. Very nice use of indirect question here! Even native speakers mess that up.

He was so good at calculations that even adults were surprised. Young Ino Tadakaka was so good ... He was so good at calculations that even adults were surprised. Young Ino Tadakaka was so good ...

He probably had a desire to continue studying and become a scholar. Yes. Or "He likely ..." He probably had a desire to continue studying and become a scholar. Yes. Or "He likely ..."

However, at the age of 18, he got married at his parents’ request. Yes. "request" or "demand" ? However, at the age of 18, he got married at his parents’ request. Yes. "request" or "demand" ?

（His original name was Koseki- [小関].) （His original name was Koseki [小関].)

When you have a sentence that would result in parentheses within parentheses, you use square brackets instead.

Later, he decided to study again while traveling, and he devoted himself to learning, even sacrificing sleep. A one-word adverbial for time or location doesn't require a comma, but the comma is okay. Later, he decided to study again while traveling, and he devoted himself to learning, even sacrificing sleep. A one-word adverbial for time or location doesn't require a comma, but the comma is okay.

It is said that he walked about 40 kilometers every day. Yes. Ideally, you would specify *who* said this, but this is absolutely fine. Alternative: He is said to have walked about 40 kilometres every day. It is said that he walked about 40 kilometers every day. Yes. Ideally, you would specify *who* said this, but this is absolutely fine. Alternative: He is said to have walked about 40 kilometres every day.

In this wayThrough these efforts, he succeeded in creating a complete map of Japan. Through these efforts, he succeeded in creating a complete map of Japan.

"In this way" works too, the correction just makes it more descriptive.

In this way, he succeeded in creating a complete map of Japan. Or "Using this methodical approach, ... In this way, he succeeded in creating a complete map of Japan. Or "Using this methodical approach, ...

Although he died at 72, his companions carried on his work and completed the map. Although he died at 72, his companions carried on his work and completed the map.

At that time, the average life expectancy was around 50 (years old), yet Tadataka continued to travel across the country with a positive attitude and great dedication. At that time, the average life expectancy was around 50 (years old), yet Tadataka continued to travel across the country with a positive attitude and great dedication.

If I were in his position, I might think that at 50 it would be too late to learn something new and give up. If I were ... (nice use of subjunctive!) Alternative construction using past tense: Had I been in his position, I might have thought that age 50 was too late to learn new things and have given up. If I were in his position, I might think that at 50 it would be too late to learn something new and give up. If I were ... (nice use of subjunctive!) Alternative construction using past tense: Had I been in his position, I might have thought that age 50 was too late to learn new things and have given up.

And yet, he devoted his time and energy to creating a map of Japan with determination and optimism. I recommend looking for alternatives to pronouns at time. For example, "And yet, this inspiring man ..." Or "And yet, this courageous scholar ..." And yet, he devoted his time and energy to creating a map of Japan with determination and optimism. I recommend looking for alternatives to pronouns at time. For example, "And yet, this inspiring man ..." Or "And yet, this courageous scholar ..."

I believe that this achievement was made possible by his truly noble spirit. Yes, and very nice! I believe that this achievement was made possible by his truly noble spirit. Yes, and very nice!

The person who spent 18 years traveling all over the country (in) this way to complete an accurate map of Japan was Tadataka Ino- (伊能忠敬). The person who spent 18 years traveling all over the country (in) this way to complete an accurate map of Japan was Tadataka Ino (伊能忠敬).

Usually you put the Japanese writing of a name in parentheses. Also "in" in the parentheses is optional here.

The person who spent 18 years traveling all over the country in this way to complete an accurate map of Japan was Tadataka Ino-伊能忠敬. The definite article here implies only one, which is likely true, but we would generally say "One person who ... I would use "create" rather than "complete" here. The person who spent 18 years traveling all over the country in this way to complete an accurate map of Japan was Tadataka Ino-伊能忠敬. The definite article here implies only one, which is likely true, but we would generally say "One person who ... I would use "create" rather than "complete" here.