well, think of a thermometer its 20 degrees during the day and then at night the temperature drops BELOW zero to -4.
Or you could think of it this way: -4 = 4 * (-1)
Perhaps you are confused about the parenthesis( )around -1. The parenthesis are merely a way of making an equation with a negative number less confusing by explicitly showing that that (-)negative sign is not a subtraction sign.
So, 1 * (-4) reads as one times negative four.