Excellent really useful for primary school kids but may be not for the lower end of primary, as it does mention reproduction etc. Can be used as a quick guide for year 7, but will need to look up more on google etc; as not in-depth enough.
Sometimes as an adult, things need to be reversed and made simpler. I find this dictionary perfect for looking up terms I am unsure of. It is a great aid for young children to use, as the pictures are very suitable and support the information.