Understanding Adding and Subtracting Fractions with Different Denominators for 12-Year-Olds

Adding and Subtracting Fractions with Different Denominators

When we add or subtract fractions, the first thing we need to remember is that they must have the same denominator. The denominator is the bottom number of a fraction, which tells you how many equal parts the whole is divided into. When the fractions have different denominators, we can't just add or subtract them right away.

Step-by-Step Guide

Step 1: Identify the Denominators

Let’s say we have the fractions 1/4 and 1/6. Here, the denominators are 4 and 6.

Step 2: Find a Common Denominator

A common denominator is a number that both denominators can divide into evenly. To find it, you can list the multiples of each denominator:

• Multiples of 4: 4, 8, 12, 16, 20
• Multiples of 6: 6, 12, 18, 24

The smallest common multiple is 12, so 12 will be our common denominator.

Step 3: Convert Each Fraction

Now we need to convert each fraction to have the common denominator:

• To convert 1/4: Multiply the numerator (1) and the denominator (4) by 3 to get 3/12.
• To convert 1/6: Multiply the numerator (1) and the denominator (6) by 2 to get 2/12.

Step 4: Add or Subtract the Fractions

Now that both fractions are 3/12 and 2/12, you can add or subtract:

• If adding, 3/12 + 2/12 = 5/12.
• If subtracting, 3/12 - 2/12 = 1/12.

Step 5: Simplify (if needed)

Sometimes, your answer can be simplified. In this case, 5/12 and 1/12 are already in their simplest forms, so we’re finished!

Conclusion

Adding and subtracting fractions with different denominators might seem tricky, but by finding a common denominator, converting the fractions, and then performing the addition or subtraction, you can do it! With practice, you'll get the hang of it!