That math especially is way behind what 8th grade kids are currently doing. Its basic arithmetic. Kids are doing that and very simple algebra in 2/3rd grade now days. In 8th grade its algebra and geometry. The Science is 7th grade stuff now, but much more simple. Today's students study the cell in depth during 7th grade, in 8th grade they move on to energy, electromagnetic waves, and lots of Chemistry. The spelling is pretty simple, kids do vocab. in almost every subject as it relates to the subject matter. The History is a bit different, more big concepts rather than memorization of specifics dates and items. There is also a lot of added geography, including cultural and religious traditions around the world. That mostly occurs in 6th grade. 8 grade is US history.
This is based on my teaching middle school in texas and florida, most states in the US are likely similar. There are also advanced classes at each grade level and subject where its much more advanced, where 'education' is 'better' you have more kids in the advanced classes, its not like its not offered in southern states, just not as many kids participate.