3 kg is generally equivalent to 12 inch birthday cake. Like the cake shop here. Eight inches is one pound, 10 inch cake is two pounds, 12 inch cake is three pounds, and 14 inch cake is four pounds.

1 inch equals 2.54 cm, from which it can be calculated that an 8-inch cake is 20.3 cm; 10 inch is about 25.4 cm, and 12 inch cake is about 30.5 cm. Generally speaking, 8 inches equals 20 centimeters. 10 inch: 25 cm; 12 inch: 30 cm.

Exercise:

1. Preparation steps. After mixing flour and cocoa powder, sieve twice for later use. Fold the oven paper into a 20X20 box and put it on the baking tray. Melt the butter. Cakesetting with a diameter of 18cm is lightly coated with a layer of melted butter, and then put in the refrigerator for later use. Preheat the oven to 170 degrees.

2. Put the eggs in a basin and break them with an eggbeater. The other pot is filled with 60-degree hot water, and the egg pot is placed on it to beat the egg liquid. After foaming, add sugar and continue stirring. When the amount of egg liquid is 3 times, remove the hot water basin below. Continue to stir the egg liquid until the egg liquid stirred by the eggbeater can write numbers, and the traces of numbers can be clearly seen when falling.

3. Pour the sifted flour and cocoa powder into two bowls and gently stir with a flat shovel. When it is stirred into a paste, add butter and stir well.