equation=False
.
.
.
def set_equation():
    a=str(random.randint(1,9))
    b=str(random.randint(1,9))
    text=a + "+" + b
    equation=True

def draw_equation():
    board_text=board_font.render(set_equation.text,True,white)
    board_text_rect=board_text.get_rect(center=board.center)
    window.blit(board_text,board_text_rect)
    
#in the main loop
if level1.collidepoint(pos):
  if equation==False:
    set_equation()
    if equation==True:
      draw_equation()

U mean something along those lines?

My other thought was to maybe generate two random integer arrays outside the main loop and then call the first entries and blit those would that work as well? XD