The first dilemma parents face is knowing whether to help or not. 

If they intervene, will they be doing more harm than good because what they learned decades ago may well not be the way their children are being taught to do things now? Another anxiety is will they even be able to do it? There are many potential pitfalls involved in helping your child that it is no surprise that often parents simply opt out and leave it up to the school to handle.

The best thing to do is not to shy away from any differences in the way maths is taught. Study them with your child. Explain to them that there are often many different ways to solve the same problem and get them to teach you the method that they have been taught if they can. Often the very act of teaching something that your child has learnt will reinforce it in the mind of the child as well as delighting them that they can actually teach their parents something.

If they are using a different way to solve a problem then this can be a bonus as you can use your method to check the answers.  

In my experience it’s always best to do than not do and certainly up to year 7/8 it’s a good idea to be routinely involved with the homework