Using headings within your content will allow you to break up the page into sub areas, which will mean your viewers will find the page easier to read, especially if they are looking for a certain section of information.
The image below shows an example of a page where sub-headings have not been used to separate the different sub-areas for each subject within the page.
The image below shows the same page using sub-headings to split the page up into sub-sections for each curriculum area, making it easier for the user to read and navigate through the content.