Adding Fractions for Kids: Same Denominator Made Easy (Grade 4 Math)

Hi, I'm Luna from DoodleBeez. Today we are adding fractions with the same denominator. That means the bottom numbers match, and I will show you a trick that makes it really easy.

First, a quick reminder. In a fraction, the bottom number is the denominator. It tells us how many equal parts the whole is cut into. The top number is the numerator. It tells us how many parts we have.

Here is a bar cut into five equal parts. Two fifths are shaded. Now let's add one more fifth by shading one more part. How many fifths are shaded now? Count them: one, two, three. Three fifths.

Here is the trick. When the denominators are the same, add the numerators and keep the denominator. Two plus one is three, and the fifths stay fifths. So two fifths plus one fifth equals three fifths.

Why don't we add the bottom numbers too? Because the size of each piece does not change. Fifths plus fifths still gives fifths. Adding the bottoms would give tenths, and that would be wrong.

Let's try another one. Three eighths plus four eighths. The denominators match, so we add the numerators. Three plus four is seven. Keep the eighths. The answer is seven eighths.

Now it's your turn. What is two sixths plus three sixths? Pause and try. The sixths match, so add the tops. Two plus three is five. Keep the sixths. The answer is five sixths.

Great job! Remember, when the denominators match, add the numerators and keep the denominator the same. The size of the pieces never changes. Practice adding fractions in the Math Lab at doodlebeez.com. See you next time!