ESTIMATION PRACTICE · SET 052
The big and the small
Move between a working ship, a tennis tournament and an ear of corn. These three questions practise estimation when you have a useful mental model but do not know every input. Each asks for a count, yet the way you break the total down changes from one question to the next.
Three questions · Untimed solo practice · Calculator and scratch notes available
Answers and worked explanations appear after you submit each estimate. Replaying keeps your first completed score.
Questions and ways to approach them
QUESTION 1 · World
Roughly how many sailors and aircrew live aboard a deployed Nimitz-class aircraft carrier?
Answer in: people
Separate the people operating the ship from the people supporting its aircraft. Estimate the size of each group before adding them. Check whether your total describes everyone aboard or only one part of the crew.
QUESTION 2 · Sport
How many double faults were recorded in the 2026 US Open men’s singles main draw?
Answer in: double faults
Start with the structure of a knockout tournament. Estimate the number of matches, then choose a plausible average per match. Match lengths vary, so treat the average as your main source of uncertainty.
QUESTION 3 · Nature
Roughly how many kernels are on a typical ear of sweet corn?
Answer in: kernels
Picture the kernels as rows wrapped around the cob. Estimate rows and kernels per row separately. Compare the result with the size of a cob you have actually held, rather than treating the whole ear as one unstructured number.
Review the reasoning, then try again
A close answer is useful, but so is knowing where an estimate went wrong. After each reveal, compare your assumptions with the worked explanation. Look for a unit conversion, a repeated factor or an uncertain starting value before deciding what to change on a replay.
Each round scores the ratio of the larger number to the smaller. A perfect estimate is 1×. Your three-round score is the arithmetic average of those ratios, so a large miss can outweigh two close answers. Read the scoring rules and examples.