THE CRA PERSPECTIVE Ancient Engineering Wonders That Still Challenge Our Imagination From underground cities and precision-cut stone to monumental temples and sophisticated water systems, the ancient world was far more technologically capable than we sometimes imagine. Some of humanity's greatest engineering achievements were built long before modern machines, computers and industrial technology. Across continents, ancient civilizations transformed stone, mountains, water and landscapes into extraordinary structures. Their achievements reveal not only physical strength, but also planning, mathematics, craftsmanship, environmental awareness and generations of accumulated knowledge. These monuments invite us to ask an intriguing question: How did ancient societies accomplish eng...
Mathematics is often considered challenging, but it’s also filled with fun tricks and shortcuts that can make solving problems quicker and more engaging. Here are ten fascinating math tricks that you can easily share or use to sharpen your math skills. 1. The Rule of 11 for Quick Multiplication Want to multiply any two-digit number by 11? Here's a quick trick: Separate the digits of the number. For example, for 54, write it as 5 and 4. Add the two digits: 5 + 4 = 9 5 + 4 = 9 5 + 4 = 9 . Place this sum between the original digits: 594 594 594 . So, 54 × 11 = 594 54 \times 11 = 594 54 × 11 = 594 . If the sum of the digits exceeds 9, carry the extra digit over to the first number. 2. The Magic of 9 in Multiplication The number 9 is magical in multiplication: Multiply any number by 9, and the sum of the digits in the result will always equal 9. Example: 9 × 7 = 63 9 \times 7 = 63 9 × 7 = 63 , and 6 + 3 = 9 6 + 3 = 9 6 + 3 = 9 . 3. Squaring Numbers Ending in 5 For any two-digit number e...