OAS 5.GM.3.5 (Oklahoma, 5th Grade): "Estimate lengths and geometric measurements to the nearest whole unit, using benchmarks in customary and metric measurement systems." The worksheets below practice this standard. Each one is a free printable PDF with an answer key, comes in multiple versions, and can also be assigned digitally - no login or account needed.
Geometry & Measurement (GM)5.GM.3 Understand angle, length, weight, and capacity as measurable attributes of real-world and mathematical objects, using various tools to measure them. Solve real-world problems of length.5.GM.3.5Estimate lengths and geometric measurements to the nearest whole unit, using benchmarks in customary and metric measurement systems.