We are pretty sure three-significant-figure prices like $843, $75.10 and $9.22 should not be considered round, since they begin with “high” digits (‘9’, ‘8’, ‘7’ etc). However, should be $17.50 and $222 be considered round?

Our first answer is another no. If round prices have only one or two significant figures will easier for our brains to recognize them. Following this simple rule, $220 would be round, $222 wouldn’t. We would still not be sure whether $290 is a round price. For that we need to know, first, the “discount” limit. And then memorize some numbers and patterns. Nonotheless,, but $299, for sure, wouldn’t.

A

But since you continue to read this page, let’s talk about exceptions. We have being observing, from time to time, prices like $12.49, which is just below $12.50. By default, $12.50 would not be considered round. Therefore, $12.49 would not be just-below, but a complicated one.

As we will see in the next page, a price is just below when in relation to a round price. If a price is just below only in relation to complicated prices, it cannot be just-below. It remains complicated. For instance, $842.99 is just below $843. Since, $843 is complicated by default, $842.99 is complicated by default as well.

Nevertheless, $12.50 falls in a couple of categories of three-significant-figure prices that might be considered round. The first category is the prices beginning with ‘1’, and the second category is the prices whose significant figures end in 5.

If we take the significant figures of $12.50 and transform it a integer number [125], it will end in ‘5’. The same happens with $2.05 [205] , $3,350 [335] and $545 [545]. All theses numbers are exactly half of a two-significant-figure number [250], [410], [670] and [1090