What do the question marks on these gas station signs mean?


![Gas station signs](https://i.stack.imgur.com/KY5kp.jpg)

> ハイオク： １４８？  
>  レギュラ： １３７？  
>  軽油： １１５？

What meaning do the question marks have?




I traced the photo to [this place](http://gogo.gs/rally/2399000021.html) in
Okazaki (Aichi prefecture): ![photo of the gas
station](https://i.stack.imgur.com/4aU1K.jpg)

On their web page, they claim to offer the cheapest gas based on a crowd-
sourced survey of gas prices elsewhere in Japan. The numbers shown on the
signs are based on these survey results:

> 一番安いガソリンスタンドはここ！皆さんから投稿された全国のガソリン価格口コミ情報をリアルタイムにお届け！

Further down the page, it mentions that the prices are rounded up to the
nearest whole yen, which is why there are question marks displayed instead of
numbers:

> 小数点以下を切り上げる

As you can see, the price at the bottom of the sign is for 18 litres of
kerosene (灯油). This number has no decimal point, so the last digit hasn't been
replaced.

As Dave suspected, these question marks have very little to do with 日本語 at any
level. But I hope someone finds this useful and/or interesting :-)




I traced the photo to [this place](http://gogo.gs/rally/2399000021.html) in
Okazaki (Aichi prefecture): ![photo of the gas
station](https://i.stack.imgur.com/4aU1K.jpg)

On their web page, they claim to offer the cheapest gas based on a crowd-
sourced survey of gas prices elsewhere in Japan. The numbers shown on the
signs are based on these survey results:

> 一番安いガソリンスタンドはここ！皆さんから投稿された全国のガソリン価格口コミ情報をリアルタイムにお届け！

Further down the page, it mentions that the prices are rounded up to the
nearest whole yen, which is why there are question marks displayed instead of
numbers:

> 小数点以下を切り上げる

As you can see, the price at the bottom of the sign is for 18 litres of
kerosene (灯油). This number has no decimal point, so the last digit hasn't been
replaced.

As Dave suspected, these question marks have very little to do with 日本語 at any
level. But I hope someone finds this useful and/or interesting :-)

