God it was you that made me laugh on the ISP internet threads wasn't it 
OK - I'm going to try and explain this "primary school" age thing again.
Next year my DS2 goes up to Junior school (YR3) and into KS2. DS1 will be in YR6 - also KS2.
They will both be working at the stage KS. Their teachers will probably use many of the same resource packs for them.
However, DS2 will not be having the same resources used for his lessons in, lets just say, Maths, as DS1 will be in YR6. The packs are provided to cover and entire Keystage..........and so include material for all of the ages from YR3 to YR6 (8-11).
While DS1's teacher will be teaching him square numbers, recognising divisibility and other such more complicated/complex areas
DS2 will be doing adding and subtracting multiples of 10, counting back in hundreds, and the like.
The resource packs the teacher use will probably be the SAME one - they just take the information and resources that are most suitable for the age group they are teaching out and use that - leaving the stuff that's better for the older KS2 children for the YR6 teachers to use.