Grade 4 Fractions: Adding and Subtracting Like Denominators Made Simple

➕ Adding Fractions with Like Denominators ➕

Adding fractions with the same denominator is super easy! The denominator stays the same, and you just add the numerators. Think of it like adding slices of the same pizza!

Here's the rule:

If you have two fractions, $\frac{a}{c}$ and $\frac{b}{c}$, then:

$\frac{a}{c} + \frac{b}{c} = \frac{a+b}{c}$

Example:

Let's add $\frac{1}{4}$ and $\frac{2}{4}$.

• The denominator is 4 (it's the same for both fractions).
• Add the numerators: 1 + 2 = 3
• So, $\frac{1}{4} + \frac{2}{4} = \frac{3}{4}$

# Python example to add fractions
def add_fractions(num1, den1, num2, den2):
 if den1 != den2:
 return "Fractions must have the same denominator"
 else:
 sum_num = num1 + num2
 return f"{sum_num}/{den1}"

# Example usage
result = add_fractions(1, 4, 2, 4)
print(result) # Output: 3/4

➖ Subtracting Fractions with Like Denominators ➖

Subtracting fractions with the same denominator is very similar to adding. The denominator stays the same, and you subtract the numerators.

Here's the rule:

If you have two fractions, $\frac{a}{c}$ and $\frac{b}{c}$, then:

$\frac{a}{c} - \frac{b}{c} = \frac{a-b}{c}$

Example:

Let's subtract $\frac{3}{5}$ and $\frac{1}{5}$.

• The denominator is 5 (it's the same for both fractions).
• Subtract the numerators: 3 - 1 = 2
• So, $\frac{3}{5} - \frac{1}{5} = \frac{2}{5}$

# Python example to subtract fractions
def subtract_fractions(num1, den1, num2, den2):
 if den1 != den2:
 return "Fractions must have the same denominator"
 else:
 diff_num = num1 - num2
 return f"{diff_num}/{den1}"

# Example usage
result = subtract_fractions(3, 5, 1, 5)
print(result) # Output: 2/5

🍕 Practice Time! 🍕

Try these problems on your own:

1. $\frac{2}{7} + \frac{3}{7} = ?$
2. $\frac{5}{8} - \frac{2}{8} = ?$
3. $\frac{1}{3} + \frac{1}{3} = ?$

Adding and subtracting fractions with like denominators is all about keeping the denominator the same and adding or subtracting the top numbers (numerators)! Keep practicing, and you'll become a fraction master! 🌟