You can draw it on the whole sheet of paper. The brain is also growing in the child’s growth period. In a time it covers the entire surface of the skull, that’s why the size of it is corresponding. Use a big oval to depict its shape.
There goes a gyrus in the middle of the organ which devides it into the left and the right sides.
The organ is not perfectly round, it looks like a walnut kernel. Start correcting the contours, making them wavy.
Add some gyruses which can connect with each other.
Continue drawing the contours in the form of the wavy lines.
The left brain is smaller, we don’t see it completely.
Correcting the drawing
Erase the lines of the oval, but do it carefully not to damage the drawing.
Add some more small gyruses in the form of short strokes.