An engineer is designing a new sustainable drainage system in Singapore. They need to find the smallest four-digit number that is divisible by both 7 and 13. What is this number?

Thu, 30 Apr 2026 18:44:20 +0000

**Why the Smallest Four-Digit Number Divisible by 7 and 13 Matters—Even in Singapore’s Sustainable Future**
Finding a four-digit number divisible by both 7 and 13 might seem like a niche math problem—but in today’s world of sustainable innovation, such precision carries real-world implications. In Singapore, where urban planners and engineers integrate advanced drainage systems into dense cityscapes, identifying exact thresholds for water flow efficiency, material thresholds, and infrastructure planning is critical. Knowing the smallest such number helps optimize designs that align with environmental goals—ensuring efficient runoff management in a city constantly adapting to climate challenges. For curious readers and professionals, this seemingly simple calculation unlocks deeper insight into how numbers shape cutting-edge urban solutions. **The Rise of Sustainable Drainage: Why Singapore Leads the Way**
Singapore’s approach to sustainable drainage systems (SDS) exemplifies innovation at scale. The city-state’s engineers face dual pressures: high population density and the urgent need to manage monsoon-driven rainfall without overwhelming concrete infrastructure. By embedding smart hydrological design, they aim to reduce flooding risks, recharge groundwater, and support green urban spaces. Behind every resilient system lies meticulous math—calculating flow rates, permeability thresholds, and timing of water retention—factors where multiples like 7 and 13 emerge naturally. Engineers use such precise numbers to synchronize modular components, often entering complex constraints that require exact divisibility for streamlined scalability. This is why solving for the smallest four-digit number divisible by both 7 and 13 offers a glimpse into real-world engineering rigor. **What Is the Smallest Four-Digit Number Divisible by Both 7 and 13? The Calculation Explained**
The key to unlocking this number lies in finding the least common multiple (LCM) of 7 and 13, then locating the smallest four-digit multiple. Since 7 and 13 are prime, their LCM equals their product: 7 × 13 = 91. Now, identify the smallest four-digit number div