Dear Alfred,
You will need to add a dataview on the page and use microflow as the source of the dataview. You will also need a non-persistent entity with an attribute of the type decimal.
Inside the microflow, create the object of this new type, change the value of the attribute as this variable and pass the object as return parameter in the end event of the microflow
On the Page, now you can display the attribute of the non-persistent entity you created.
Hope this helps.
-Shekhar