You may access Equatio Mathspace from wherever you are building your content.  From Google Docs, open Equatio, and select ‘Insert Mathspace.’  Choose the ‘Smart Shapes’ drawer and select ‘Number Line.’  You may customize your number line by using the menu to add more ticks.  In this example, I am going to choose 5.  I am then going to select the Equation Editor & type in the letter ‘x.’  I can then use my copy and paste tools to add more x’s and then align them above the ticks.  When finished, insert your line plot back into the Google document.