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Why you understand math in class but not at home

It made total sense when the teacher did it on the board. Then you sit down at home, look at problem 1, and have no idea where to start. This is one of the most common things in math, and it doesn't mean you're bad at it. It means something specific is missing, and you can fix it.

Why it happens

Following isn't the same as doing

Watching someone solve a problem, you only have to agree with each step. Doing it, you have to come up with each step. The first feels like understanding, and it is a kind of understanding, but it's not the kind the homework asks for.

In class, someone else picks the next step

The hardest part of most problems isn't the arithmetic. It's deciding what to do next: factor or expand, subtract first or divide first. In class the teacher makes that choice. At home, you do, for the first time.

The homework isn't the example

Homework problems are usually a little different from the ones in class: a negative where there wasn't one, the unknown in a different place, a word problem around it. A small change can make a familiar method look unfamiliar.

Your notes say what, not why

Most notes copy the steps. A few hours later, "−3 both sides" doesn't tell you why it was −3, so you can't do it when the number changes.

An older gap is hiding underneath

Sometimes the new idea is fine and an old skill is the problem: fractions, negative numbers, distributing. In class the teacher does those bits for you. At home they trip you up, and it feels like you don't get the new topic.

There's no one to ask

In class, you can put your hand up. At home, a five-second question can turn into a 30-minute stall.

Six fixes

  1. Try the example before the teacher finishes it. When a new example goes up, try the next step in your notebook before they write it. Being wrong in class is cheap, and it's the same practice the homework needs.
  2. Write the why next to the steps. One short note per step: "subtract 3 to get x alone", "flip the sign: dividing by a negative". That's what makes notes useful at home.
  3. Start the homework the same day. Do even one problem within a few hours of class, while it's fresh. The longer you wait, the more of it fades.
  4. Compare the problem to the example. When you're stuck, put the class example next to the homework problem and find the exact difference. That difference is usually the whole difficulty.
  5. Find the older skill. If you keep stalling on the same kind of step, ask which earlier skill it needs and practise just that for ten minutes. It often fixes everything above it.
  6. Write down the exact question. If you're still stuck, write "I don't get why line 3 becomes line 4" and bring it to class. It gets you a far better answer than "I didn't get the homework".

Check it worked

The next day, do one of last night's problems again on blank paper with your notes closed. If you can, you've got it, at home as well as in class.

Where theoremEd fits

theoremEd is the person to ask at home. It reads the problem on your screen in Chrome or on a Mac, looks at where you got to, and asks one question at a time to get you to the next step. If an older skill is the problem, it points you to a short lesson on it. It never gives the answer, so you still do the thinking. Try it on the homepage, free, no account.