To display a sensor reading on the screen of the EV3, you must configure the Display block to allow sensor readings to be wired as input:

1. Drag a Display block onto the programming canvas.
2. Click the Folder button and select Text>Pixels.
3. Click MINDSTORMS (in the upper-right corner of the block), and select Wired as the text input.
4. Once you select Wired, a Text port will appear on the block. Connect your data from the Vernier block to the Text port on the Display block.

The Vernier sensor block for EV3 MINDSTORMS can be found here:
https://www.vernier.com/engineering/lego-ev3/ev3-sensor-block/

LEGO^® MINDSTORMS^® Education EV3 Core Set with Charger (LEGO-EV3-CORE)
NXT Sensor Adapter (BTA-NXT)
Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3 (EP-EV3-E)
LEGO® Mindstorms® EV3 Troubleshooting and FAQs