# When I delete an equation, the equation numbers aren't updated

In Writer, I have entered some equations after typing "fn" and then pressing F3, to get equation numbers on the right. SoI have equations 1 through 7, say. If I now delete equation 5, the numbers on the last two equations are still 6 and 7. I can type over them to make the numbers 5 and 6, but then next equation I enter will still be numbered 8. I deleted the equation by just highlighting and pressing the Delete key. What should I have done?