Khan Academy is an amazing and free website for Maths, Science and more, and there are all sorts of years or grades to choose from. They also have videos and lessons to help you learn. If your someone who doesn't have any idea how to do Math, there are videos to help you, and if your stuck, you can get a hint. If you get a question right, this circle icon turns green, but if you get it wrong it turns grey.
Starting from a very early age, Kumon Workbooks are a great way to allow your kids to learn English vocabulary skills like reading, grammar, spelling, and writing.
Each new subject has an explanation and examples to allow the student to understand the concept. This is followed by lots of questions and practical exercises to check their understanding.
The answers are also in the back of the book for checking.
There are a large number of books that run in a logical sequence. Each book has a reference to the student's grade level or age.
Dad's Tips - These are well-structured books that should be used every day to fast-track your child's vocab skills. With a little dedication and routine, you will find that they will soon shoot ahead of the level of English comprehension expected at school.
It is also important that your child learns using a book and pencil as much as possible, as opposed to learning solely online. This will help to reduce their screen time.