I hear your frustration and I applaud you for stepping in to help your son.  He is lucky to have you.

First of all your son sounds like many other normal second grader boys.  They would rather be playing then completing a worksheet.  Also, if you are concerned that he might fail, schedule an appointment for a parent teacher conference right way.  Yu need to understand what the teacher is seeing or not seeing.  Ask for specific weakness and strenghts.  Also, you need to find out what the teacher or school is doing to help your son.  The more you know the better you can support your son as well as re enforce what the teacher is doing.

Here are some things you might want to give a try.  Please know that some of them might sound a little out of the box, but try ti keep an open mind.

You said that your son says he has trouble with understanding directions.  

Let him practice following directions in a creative way.  Go to the public library and check out some how to orcraftbooks that he finds interesting.  For example, a book on origami could be fun.  Get lots of paper and have him a read the direction, following the pictures to make the different shapes.  Or if he is interested in knots, you can find a book that has all different types of knots set by step that he can read and tie on his own.  Yu can do the first one or two with him, then give him the challenge to figure out someonhis

Magic tricks are always fun for kids.  Find another book that explains simple tricks for beginners.  Ask your son to read the direction .  Then after practicing it, he can performing it for the family.

If he likes to cook, let him help you make some meals.  Let him pick put the recipes, gather or shop for the ingrediaence and then you can help him putt all
together.

Telling jokes is another way that is fun for him to follow steps.  A joke is only funny when it is told in order like directions.  Find a kid appropriate joke book or online website.  Have him read the jokes.  Tell him he needs to tell at least one joke each night at dinner.

Hopefully, one of these ideas will work or spark a new idea that better suits your son.

Also, I encourage you to read to your son daily.  He isn't too old and won't be until he is 21 and out of the house.  He him books he finds interesting which maybe nonfiction like trucks or fishing.  Not only are you modeling what good readers do and good reading habits, you are building upon your relationship.  Everything you read allows you to have many conversations comparing text, connecting it to the real world, or just having fun.

Good luck and remember your son is luck to have you there to help him.

Barb K
Www.LessonPop.com