def what_does_sum_approach(self):
    morty = self.morty
    rects = self.rects
    cross = TexMobject('\\times')
    cross.replace(self.sum_word, stretch=True)
    cross.set_color(RED)
    brace = Brace(self.integral, DOWN)
    dt_to_0 = brace.get_text('$dt \\to 0$')
    distance_words = TextMobject('Area', '= Distance traveled')
    distance_words.next_to(rects, UP)
    arrow = Arrow(distance_words[0].get_bottom(), rects.get_center(), color=WHITE)
    self.play(PiCreatureSays(morty, 'Why not $\\Sigma$?', target_mode='sassy'))
    self.play(Blink(morty))
    self.wait()
    self.play(Write(cross))
    self.wait()
    self.play(RemovePiCreatureBubble(morty, target_mode='plain'), *list(map(FadeOut, [cross, self.sum_word, self.ticks, self.dt_brace, self.dt_label])))
    self.play(FadeIn(brace), FadeIn(dt_to_0))
    for new_rects in self.rect_list[4:]:
        rects.align_submobjects(new_rects)
        for every_other_rect in rects[::2]:
            every_other_rect.set_fill(opacity=0)
        self.play(Transform(rects, new_rects, run_time=2, lag_ratio=0.5), morty.look_at, rects)
        self.wait()
    self.play(Write(distance_words), ShowCreation(arrow), morty.change_mode, 'pondering', morty.look_at, distance_words)
    self.wait()
    self.play(Blink(morty))
    self.wait()
    self.area_arrow = arrow
def what_does_sum_approach(self):
    morty = self.morty
    rects = self.rects
    cross = TexMobject('\\times')
    cross.replace(self.sum_word, stretch=True)
    cross.set_color(RED)
    brace = Brace(self.integral, DOWN)
    dt_to_0 = brace.get_text('$dt \\to 0$')
    distance_words = TextMobject('Area', '= Distance traveled')
    distance_words.next_to(rects, UP)
    arrow = Arrow(distance_words[0].get_bottom(), rects.get_center(), color=WHITE)
    self.play(PiCreatureSays(morty, 'Why not $\\Sigma$?', target_mode='sassy'))
    self.play(Blink(morty))
    self.wait()
    self.play(Write(cross))
    self.wait()
    self.play(RemovePiCreatureBubble(morty, target_mode='plain'), *list(map(FadeOut, [cross, self.sum_word, self.ticks, self.dt_brace, self.dt_label])))
    self.play(FadeIn(brace), FadeIn(dt_to_0))
    for new_rects in self.rect_list[4:]:
        rects.align_submobjects(new_rects)
        for every_other_rect in rects[::2]:
            every_other_rect.set_fill(opacity=0)
        self.play(Transform(rects, new_rects, run_time=2, lag_ratio=0.5), morty.look_at, rects)
        self.wait()
    self.play(Write(distance_words), ShowCreation(arrow), morty.change_mode, 'pondering', morty.look_at, distance_words)
    self.wait()
    self.play(Blink(morty))
    self.wait()
    self.area_arrow = arrow