Understanding Ratios in Grade 7 Math: Solving for the Number of Girls

In a 3:4 ratio of boys to girls, if there are 21 boys, we can solve for the number of girls using the ratio.

Using the given ratio, we find the total parts is 3 + 4 = 7. To find the number of girls, we divide the total number of parts by the number of parts representing girls: 4/7 * 21 = 12 girls.

Therefore, in this scenario, there are 12 girls.

Remember, ratios are a key part of understanding proportions and are fundamental to many mathematical concepts.