Fame is not a scale
The Statue of Liberty is more famous, to many players, than its height. With the pedestal, ground to torch, this board uses about 93 metres. The Eiffel Tower to the antennas is about 330 metres. Nothing about postage, film, or a school poster prepares you for a factor of roughly three and a half. The poster made both of them 'big.' Big is not a measurement. When the red outline lands, the embarrassment is specific: you knew both objects and still missed the multiple.
The same thing happens with animals people have only seen in documentaries. A blue whale at 27 metres is a large adult on this board, not the longest whale ever claimed. A school bus at 12 metres is a full-size bus. The whale is 2.25 buses. Players who say 'several buses' are often picturing four or five, because 'several' is doing the work of a number. The game is a request to retire that word.
The crop is the lie
Textbooks, trailers, and atlas pages frame the subject to fill the rectangle. A rocket fills a page. A country fills a page. A player fills a page. The frames are not on one scale, and the eye quietly treats them as if they were. Size It Up refuses the separate frames. One ground line, one scale, two cut-outs. If the small one becomes a crumb, that is the size. Zoom exists so you can inspect the crumb. It does not change the ratio.
Area makes the crop worse. Texas land area is about 696 thousand square kilometres. Metropolitan France is about 552 thousand. Printed maps often scale each region to the same box, so France can look like Texas's peer in a way the areas do not support. Texas is larger, and not by double. Players who answer 'Texas is twice France' are answering the box, not the land. The compare stage draws the square root so both shapes fit, and the printed ratio stays the area ratio. Read both.
Why the score uses a ratio
A metre of error on a penguin is a disaster. A metre of error on a container ship of about 400 metres is noise. Absolute error would praise people for picking large targets and punish people for picking small ones. The ratio does not. Half the penguin and half the ship are the same miss, and both score 45. Double is the same miss in the other direction. Within 6 percent scores 100, whether the object is a ball or a tower.
The steps in between are on a log scale. About 12 percent off scores 90. About 20 percent scores 78. Four-to-three scores 62. Triple scores 30. Five times off scores 0. A player who is consistently 'about double' is not guessing at random. They are one stable misconception away from a sharp score. That is a kinder and more honest grade than a linear metre count, and it matches the way the slider moves: equal travel, equal ratio.
Axis mistakes look like size mistakes
A hoop is 3.05 metres to the rim. A door in your house is not a mystery, until you compare it with a hoop and discover your door memory was 'person-sized' rather than a number. Sport questions say across, tall, or long. A size-5 soccer ball is 0.22 metres across. If you answer with a feeling about 'a ball' you will mix the soccer ball, the basketball at about 0.24 metres, and the distance to the rim. Those are three different questions. The heading is the question.
Geography is where this bites hardest. Chile's mainland reach, north to south, is about 4,270 kilometres. That does not make Chile larger in area than a compact country with a shorter reach. Italy's mainland boot is about 1,180 kilometres long. Three Italies end to end still do not tell you Italy's area. The library will not pair a length with an area. Your mouth might. If the round says area, stop using the word long.
A small set of units beats a large set of facts
You do not need fifty memorised lengths. You need a few you can see. A hoop at 3.05 metres. A bus at 12. A Liberty-with-pedestal at 93. A whale at 27, which is 2.25 buses. New objects then become multiples of a unit you trust. The black reference on a scored round is that method, handed to you. The white silhouette is you applying it. The red outline is the correction when the multiple was wrong.
Unlimited is where a unit gets installed. The daily five is where it gets tested, under weights that make the last rounds matter: one, one, two, three, three. Looking up today's answers first skips the test. Comparing two truths on the compare page, without opening today's target, builds the unit. The order is the whole method. Fact, then eye, then grade. Not grade, then excuse.