See if this reply helps.
You drew the schematic for a non-inverting op-amp with a gain of 2;
GAIN equals 1 + (ResistorTOP / ResistorBOTTOM). If ResistorTOP = ResistorBOTTOM then overall gain is 1 + 1.
If you use the schematic for the yes-inverting op-amp, then you can have a gain equals (ResistorTOP_FEEDBACK divided by ResistorBOTTOM_INPUT), and this can be 1/2 = half, but the signal is inverted or (times -1). You can use two op-amps in the yes-inverting config. First op-amp achieves -1/2, and the second op-amp achieves times -1 (for an overall gain of positive 1/2).
The last suggestion is: if the input signal is not very delicate, then use a RESISTOR voltage divider that cuts the INPUT signal in half, then apply it to a non-inverting OPAMP circuit of times 1. Voltage at the divider comes from : voltage IN x RESISTOR BOTTOM divided by (RESISTOR BOTTOM + RESISTOR TOP).