A shopkeeper in a market wrote this sign noting the price of horns so commonly used in demonstrations these days across the country. It was supposed to be a joke based on grammatical error, but like in many cases, it reveals a lot about society, culture and power relations.
In Hebrew, the noun following a number up to ten should be in plural form. After ten, the noun can be in plural or singular form. Hebrew is also a highly gendered language, and since our currency, the Shekel, is considered male, it should be followed by ה (pronounced as "ah"). Therefore, an item that costs 10 Shekels should be written as עשרה שקלים. However, it's common for Israelis to say עשר שקל, even though it's technically incorrect.
The connection between ‘proper’ grammar and class is well documented, and Hebrew is no exception. Those who call out grammatical errors in Hebrew are usually middle or upper class, which is mostly Ashkenazi. Speaking with grammatical errors is usually attributed to lower classes, which are usually Mizrachi Jews (and of course, Palestinians). This ethnic divide is not as strong as it used to be, but it still exists.
When the shopkeeper suggests the price for protesters against Netanyahu is - עשרה שקלים (Asara Shkalim) he is referring to the fact that the Israeli center who rose up in protests against Netanyahu is predominantly middle and upper class (not counting the settlers, who are wealthy but for obvious reason support him). The price for supporters of Netanyahu is written - עשר שקל (Eser Shekel) due to the strong support Netanyahu enjoys amongst Jews of lower class in the social periphery of Israel.
This supposed simple joke carries with it strong classist and ethnic assumptions, revealing the frequent connection between language and culture. For many people it will be seen as offensive (and rightly so), Some will obviously laugh, but for Hebrew speaking Israelis the implication is immediately understood. The idea that there is a "proper" grammar for a language is absurd since languages evolve over time and belong to their speakers. The adherence to grammatical correctness is often used as a tool for middle and upper class people to distinguish themselves from those they perceive as inferior. In times of political and social turmoil, language reveals underlying ethnic and class tensions in our politics.