英和和英

to fasten a coat with buttons―button up a coat

undo the buttons of

to undo a button―unbutton one's coat

to undo a button―（上衣のボタンなら）―unbutton one's coat

push the button down

to sew on a button

to sew a button on

press a button

fasten buttons

to fasten one's coat with buttons―button one's coat

provide with buttons

to press the button

A button comes undone―（靴のボタンなら）―A shoe comes unbuttoned.

to press a button

sew the button down

fasten with buttons

push the shutter

sew a button on

A button has come off

A button is off.

A button comes off.

squeeze the trigger

A button comes undone

A button fell off.

disengage the gears

disengage the gears

not worth a button

four operations

addition, subtraction, multiplication and division―the four rules of arithmetic

white-out the typo