How big an area on earth would one trillion peas cover?

I solve this problem in two steps: Step 1: How much space does one pea take up? Step 2: How much space does 1 trillion peas take up? 1) How much space does one pea take up? I will assume one pea would occupy a square area 5 mm by 5 mm, which equals 25 mm2. 2) A trillion peas, requires me to use scientific notation, 1 trillion = 10^12. So our trillion peas takes up 25 *1012 mm2. Now 1 m = 1000 mm, so 1 m2 = 10^6 mm2, and 1 km = 1000 m, so 1 km2 = 10^6 m2, so 10^12 mm2 = 1 km2. Now, 25 * 1012 mm (1 km2/1012 mm2) = 25 km2 is the area on earth that one trillion peas would cover. Remember: One thousand = 103, One million = 106, one billion = 109, one trillion = 1012 Also, when you find a problem that seems too big to solve, try finding a small problem to solve, which will help you to solve the bigger one.