Manually entering a value in Manipulate interface multiplies the output

Hi, I’m a new user of Mathematica. I have a question.
When using the Plot within Manipulate, for instance with

Manipulate[Plot[Sin[a x], {x, 0, 2 Pi}], {a, 1, 10}]

all works fine if I move the slider. However, if I show the animation controls by clicking on the + on the right of the slider and enter manually the value of parameter ‘a’ instead of setting it with the slider, another twin plot appears below the current plot. I understand that this happens because the plot where I enter the value of ‘a’ becomes an Input of which the duplicate plot is the output, however I’d like to deal with just one plot. Is there a way to avoid the second plot appear when manually entering the parameter value?

Thank you in advance for your help.

Just use the Enter key after inputting the new value.

Using Shift+Enter will produce a duplicate of the Manipulate in a new output cell, as you describe.

Dear Hans, you’re right! I was actually using the Enter key in the Numeric Pad, which is indeed equivalent to using Shift+Enter. Thank you!