How to make a 2D origami ball (balloon)

(page 2)

1st picture of 2D origami ball (water bomb)

01.

Let's start with a paper's back side facing up.

Prepare to apply a horizontal "mountain-fold" in half and then unfold.

2nd picture of 2D origami ball (water bomb)

02.

Apply the horizontal "mountain-fold" in half according the step #1 and then unfold.

Prepare to apply a vertical "mountain-fold" in half and then unfold.