rough numbers

• ballparkSports venue or estimate
• estimateInformed guess at quantity
• approximationNear but inexact value
• guesstimateRough, intuitive calculation
• roundingAdjusting to simpler values

fuzzy · imprecise · spitball · back-of-envelope · eyeball · sketch · vague · loose · inexact · roundabout · coarse · handwavy · thumbnail · soft · fudge · cushion · buffer · projection

• rough estimatesrough estimate, ballpark figure, guesstimate, approximation, rough cut
• number sequencesFibonacci sequence, arithmetic sequence, prime numbers, natural numbers, integers