I want to show my daughter how to calculate addition and subtraction of fraction ,
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Let's learn about fractions! A fraction represents a part of a whole. Imagine a pizza cut into equal slices. The top number, called the numerator, tells us how many slices we have. The bottom number, called the denominator, tells us how many total slices the pizza was cut into. Here we see one-fourth, which means we have 1 slice out of 4 total slices.
Now let's learn how to add fractions when they have the same denominator. This is the easiest case! When the bottom numbers are the same, we simply add the top numbers together and keep the bottom number unchanged. Here we see one-fourth plus two-fourths equals three-fourths. We're adding 1 slice plus 2 slices to get 3 slices, all from pizzas cut into 4 equal parts.
Subtraction of fractions with the same denominator works exactly like addition! We subtract the numerators and keep the denominator the same. Here we see three-fifths minus one-fifth equals two-fifths. We start with 3 parts out of 5, take away 1 part, and we're left with 2 parts out of 5. The key is that all parts are the same size since they come from wholes divided into the same number of equal pieces.
Now let's tackle the trickier case: adding fractions with different denominators. We cannot add them directly because they represent different-sized pieces. First, we need to find a common denominator - the smallest number that both original denominators can divide into evenly. For one-half plus one-third, we need a common denominator of 6. Then we convert: one-half becomes three-sixths, and one-third becomes two-sixths. Finally, we add three-sixths plus two-sixths to get five-sixths.
Let's summarize what we've learned! When fractions have the same denominator, simply add or subtract the numerators and keep the denominator unchanged. When denominators are different, find a common denominator first, convert both fractions, then add or subtract. Here's a quick example: three-fourths minus one-eighth. Since 8 is a multiple of 4, our common denominator is 8. Three-fourths becomes six-eighths, then six-eighths minus one-eighth equals five-eighths. With practice, you'll master fraction arithmetic in no time!