What's New

Some small improvements

App Description

Zu Chongzhi was a prominent Chinese mathematician and astronomer during the Liu Song and Southern Qi Dynasties of China.

He was the first man who derived two approximations of pi, (3.1415926538932...), and his best approximation was between 3.1415926 and 3.1415927, which held as the most accurate approximation for “π” for over nine hundred years. He still had great influence on the world even nowadays.

He also made great contributions to mechanic invention, such as the South-pointing Cart, Wooden Ox And Flow Horse, Millstone with Water Power and so on.

To memorize his great contributions to science, people named the following things after him:
π≈355/113 as Zu Chongzhi's “π” ratio,
The lunar crater Tsu Chung-Chi,


With the form of drawing, this app described Tsu Ch’ung-Chi’s science achievements and life stories. It will arouse children’s interests in invention and creation!

【Characteristics of the app】

Coverage of Aristotle’s life stories
Hand drawing
Scientific history for children
Latest multimedia interactive reading experience

【Customer reviews】

The painting style could arouse kids’ infinite imagination. Marvelous!
--- Ace
My boy likes this app so much, so I download the other apps that also introduces the famous person in the world.
--- Ting
With vivid cartoons, this app suits kids the most. They can easily understand the contents.
--- Strawberry

【About us】

“Cool reading” is our principle. We are devoted to providing readers with better and newer 4D reading materials!
PS: You can retrieve all AppCarrier products by entering “xxt” in the search box.

【Contact us】

E-mail: [email protected]
Micro-blog: http://weibo.com/yidongshuyouhui

iPhone Screenshots

(click to enlarge)

Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 1 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 2 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 3 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 4 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 5

iPad Screenshots

(click to enlarge)

Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 6 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 7 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 8 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 9 Tsu Ch’ung-Chi --- Ratio of Circumference to Diameter (Audio version) screenshot 10

App Changes

  • August 05, 2014 Initial release
  • August 11, 2014 New version 1.1
  • May 05, 2015 New version 1.2
  • May 26, 2015 Price decrease: $1.99 -> FREE!
  • May 30, 2015 Price increase: FREE! -> $1.99
  • November 15, 2015 New version 2.0