Source-code to draw a hamburger:
70 REM draw hamburger
80 HGR2:HCOLOR=5
100 for t = 1 to 50 step 0.01
140 x = Sin(Tan(t))
160 y = Cos(t)
180 xp = (x * 50) + 150
190 yp = (y * 50) + 100
200 HPLOT xp, yp TO xp, yp
300 next t
http://www.calormen.com/jsbasic/
I taught some intro programming to my kid using this.