2nd Grade Subtraction Within 20 — Under the Sea Printable Math Worksheet

Make subtraction practice a splashing good time! This **Under the Sea Subtraction** printable is packed with **20 carefully leveled subtraction problems within 20**, themed around friendly sea creatures — crabs, jellyfish, starfish, and more. Perfect for **2nd-grade students** who are building fluency with basic subtraction facts. Three activity sections move from equation-solving to a write-the-missing-number challenge, keeping young learners engaged from top to bottom. Aligned to **2nd-grade subtraction fluency within 20** (supporting Common Core 2.OA.B.2). No prep needed — just print and go! Great for morning work, homework, or math centers.