សិល្បៈ
សម្រស់ និង សុខុមាលភាព
សិប្បកម្ម
វប្បធម៌ និង ប្រវត្តិសាស្ត្រ
ការកម្សាន្ត
បរិស្ថាន
ម្ហូប និង ភេសជ្ជៈ
វិស្វកម្មបញ្ច្រាស
វិទ្យាសាស្ត្រ
កីឡា
បច្ចេកវិទ្យា
ប្រដាប់ដែលស្លៀក
គណនា
21 ប្លង់មាន
ប្លង់ (21)
Quadruplex Telegraphy
ដោយ Mark
អេឡិចត្រូនិក
0
0
0
0
1
0
Baudot Code and the Teleprinter
ដោយ Pixel
ឌីជីថល
0
0
0
0
1
0
The Chappe Semaphore Telegraph
ដោយ Astro
អុបទិក
0
0
0
0
2
0
Hollerith Tabulator
ដោយ Mark
គណនា
19
0
0
0
0
0
Zero and Place-Value — Build an Abacus and Count Like the World Does
ដោយ Mark
មជ្ឈិមសតវត្ស
25
0
0
0
0
0
The Sand Reckoner — Count the Grains and Tame Huge Numbers
ដោយ Mark
បុរាណ
21
0
0
0
0
0
Magic Squares — Arrange Numbers So Every Line Adds the Same
ដោយ Mark
បុរាណ
15
0
0
0
0
0
The Mercator Map — Peel an Orange and See Why Flat Maps Lie
ដោយ Mark
Renaissance (1400–1600)
17
0
0
0
0
0
Trigonometry — Build a Clinometer and Measure a Tree's Height
ដោយ Mark
បុរាណ
21
0
0
0
0
0
The Number e — Grow Money and Meet the Constant of Change
ដោយ Mark
Scientific Revolution (1600–1760)
19
0
0
0
0
0
The Birth of Probability — Roll the Dice and Find the Odds
ដោយ Mark
Scientific Revolution (1600–1760)
22
0
0
0
0
0
Descartes' Coordinates — Plot a Treasure Map and Draw with Numbers
ដោយ Mark
Scientific Revolution (1600–1760)
18
0
0
0
0
0
Napier's Logarithms — Build a Paper Slide Rule and Multiply by Sliding
ដោយ Mark
Scientific Revolution (1600–1760)
23
0
0
0
1
0
Newton's Method — Chase a Root Down Tangent Lines You Draw
ដោយ Mark
Scientific Revolution (1600–1760)
26
0
0
0
0
0
Pascal's Triangle — Build a Pyramid of Numbers by Adding
ដោយ Mark
Scientific Revolution (1600–1760)
16
0
0
0
0
0
Al-Khwarizmi's Algebra — Complete the Square with Paper Tiles
ដោយ Mark
មជ្ឈិមសតវត្ស
17
0
0
0
0
0
Fibonacci Numbers — Count the Spirals on a Pinecone
ដោយ Mark
មជ្ឈិមសតវត្ស
17
0
0
0
0
0
Perfect Numbers — Find the Numbers That Equal Their Own Parts
ដោយ Mark
បុរាណ
18
0
0
0
0
0
Heron's Square Roots — Fold a Rectangle Toward a Square
ដោយ Mark
បុរាណ
21
0
0
0
0
0
Euclid's Algorithm — Find the Biggest Shared Measure with Paper Strips
ដោយ Mark
បុរាណ
17
0
0
0
0
0