Video lessons

Word problems look long, but most of them follow the same four steps.

Here is one. A phone plan costs 25 dollars a month, plus 10 cents for each text. Your bill is 32 dollars. How many texts did you send?

Step one: find the question. It asks for the number of texts. Call that number x.

Step two: write what you know as an equation. 25 dollars, plus 10 cents times x, equals 32 dollars.

Step three: solve it, one move at a time. Take 25 from both sides. Now 0.10 times x equals 7. Divide both sides by 0.10. x equals 70.

Step four: check it. 70 texts at 10 cents is 7 dollars. Add the 25 dollar plan, and you get 32. It matches.

So the answer is 70 texts.

Find the question. Write the equation. Solve one move at a time. Then check. Try it on the next practice question.

The GED® Math test comes in two parts.

Part one is short, and you can't use a calculator. It checks basic number skills, like fractions, order of operations, and square roots. Plan on about 10 minutes.

In part two, you get a calculator. It's the TI-30XS MultiView. On the computer test, it opens on the screen. You also get a calculator reference sheet and a formula sheet.

A few habits help.

Type the whole expression before you press enter, and use the parentheses keys. The calculator follows the order of operations, so 3 plus 4 times 2 gives 11, not 14.

For a fraction, use the fraction key, not the divide key, when you want the answer to stay a fraction.

For a negative number, use the small negative key, not the minus key.

And when you get an answer, ask yourself if it makes sense.

The calculator saves time, but it doesn't do the thinking. Practice with it before test day. GED.com has a free calculator tutorial.

On the Reasoning Through Language Arts test, you write one essay. You get 45 minutes.

You'll read two short passages that take opposite sides. Your job is to explain which side is better supported by evidence. It doesn't have to be the side you agree with.

Spend the first 5 minutes on a plan.

First, write each writer's main claim in a few words.

Second, list the evidence each one uses. Facts, numbers, and expert sources are strong. Feelings and guesses are weak.

Third, pick the side with stronger support. That's your thesis.

Now you have a simple outline. An opening that states your thesis. Two or three body paragraphs, each with one reason and a quote or detail from the passages. Then a short closing.

Leave about 5 minutes at the end to reread and fix mistakes.

A clear plan makes the writing faster. Try it with the essay practice on FinishHigh.

On the GED® Reasoning Through Language Arts test, many questions ask about the main idea. That is the one big point the writer wants you to understand.

The main idea is not just the topic. The topic might be city parks. The main idea is what the writer says about them, like: city parks make neighborhoods healthier.

Here is a fast way to find it. Read the first and the last sentences. Writers often state the main idea at the start, or sum it up at the end.

Then ask: what do most of the sentences talk about? Details are the facts, numbers, examples and quotes that back up the main idea.

Let's try a short made-up passage. Fewer children walk to school than in the past. Many roads near schools have no sidewalks. Towns that added sidewalks saw more children walking again.

The main idea: missing sidewalks are a big reason fewer children walk to school. Every sentence points to that.

Sometimes the main idea is not stated. Then you put the clues together and say it in your own words. That is called an inference.

Watch for answer choices that are true but too small, like one detail. Or too big, like a claim the passage never makes. The right answer covers the whole passage.

So: read the first and last lines, find what most sentences are about, and pick the answer that fits all of it.

Some GED® Science test questions ask about the chance that a young plant or animal gets a trait from its parents. A Punnett square makes this easy.

Each parent passes on one copy of a gene. A capital letter stands for a dominant version. A small letter stands for a recessive version.

Let's use pea plants. Big T means tall. Small t means short. Tall is dominant, so a plant with even one big T is tall. A plant is short only with two small t's.

Both parents are big T, small t. Draw a square with four boxes. Put one parent's letters across the top, and the other parent's letters down the side.

Fill each box with one letter from the top and one from the side. You get big T big T, big T small t, big T small t, and small t small t.

Now count. Three of the four boxes have at least one big T. So 3 out of 4, or 75 percent, are expected to be tall. 1 out of 4, or 25 percent, is expected to be short.

The letters are called the genotype. What you can see, tall or short, is called the phenotype.

Remember, these are chances, not promises. Each new plant has the same 1 in 4 chance of being short, like flipping a coin again.

Draw the square, fill the boxes, count, and turn the count into a fraction or a percent.

Prices go up and down for a reason. The GED® Social Studies test checks if you can explain why, using supply and demand.

Demand is how much of something people want to buy at a certain price. When the price goes down, people usually buy more. When the price goes up, they usually buy less.

Supply is how much sellers are willing to sell. When the price goes up, sellers usually want to sell more, because they can earn more.

The price where buyers and sellers meet is called the equilibrium price. On a graph, it is where the supply line and the demand line cross.

Now, what changes the price? Say a freeze ruins half the orange crop. The supply of oranges falls. People still want orange juice, so the price goes up.

Now say a new study finds that blueberries are very healthy. Demand jumps. If farmers can't grow more right away, the price goes up too.

And if a factory finds a cheaper way to make phones, supply grows, and the price usually goes down.

On the test, ask two questions. Did supply change, or did demand change? Did it go up, or down? Then you can tell which way the price moves.

Less supply or more demand pushes prices up. More supply or less demand pushes prices down.