The bottom number makes the groups

A box holds 30 eggs. And 2 fifths of the eggs are brown. How many of the eggs are brown? Let's draw them. Here are all 30 eggs. That's the whole box. Look at the bottom number of the fraction. It's 5. So we split the eggs into 5 equal groups. 1. 2. 3. 4. 5. Count one group. It has 6 eggs. Every group is the same, 6 eggs. So 30 split into 5 equal groups is 6. Now the top number. It's 2. So we take 2 of the 5 groups. When 1 group has 6 eggs, 2 groups of brown eggs have 12 eggs. We can also write it as 2 fifths times 30. 30 divided by 5 is 6, so cross both out. And write 1 under the 5. And 6 over the 30. 2 times 6 is 12. 12 eggs are brown.

Your turn. The same box holds 30 eggs. And 3 fifths of the eggs are white. How many of the eggs are white? Try it first. Pause if you like. Count the white groups. 1. 2. 3. And 30 split into 5 equal groups is 6, so every group is 6 eggs. Those 3 groups are 3 fifths of the box, and we write that as 3 fifths times 30. 30 divided by 5 is 6, so cross both out. And write 1 under the 5. And 6 over the 30. 3 times 6 is 18, so 18 eggs are white. Look at the fraction one more time. The bottom number makes the equal groups. The top number says how many groups to take.