What fraction of the circle is shaded? a) 18 out of 25, b) 18 out of 24, c) 19 out of 25, or d) 19 out of 24.
Remember that when we talk about fractions, we’re talking about the parts to the
whole. And in this case, we’re talking about the shaded parts to the whole. We count the red-shaded parts. We counted six red parts and eight total parts to make up the circle. So we say that the fraction of the circle that’s shaded is six-eighths.
But when we look at our answer choices, we’re not given a choice of six-eighths. So we need to find an equivalent fraction, a fraction that means the same thing as
six-eighths. Let’s start with 18 25ths. Is six-eighths equal to 18 25ths?
Remember, when we work with equivalent fractions, we multiply the numerator and the
denominator by the same number. I recognised that six times three equals 18. Then I try to multiply eight times three. But that doesn’t equal 25. So we know that a does not work, 18 25ths.
We can try the same process with 18 24ths. We need to multiply the numerator and the denominator by the same number. Six times three equals 18. And eight times three does equal 24. This means that 18 24ths is an equivalent fraction. And it accurately represents the fraction of the circle that is shaded, making 18
24ths the correct answer.