Quantity   Component name
27 × 3 Digit 7-segment Displays (0.56" tall) http://www.aliexpress.com/item/10pcs-3bit-Common-Anode-Positive-Digital-Tube-0-36-0-36in-Red-LED-Display-7-Segment/32421631949.html?spm=2114.13010608.0.80.eIRqCi
9 × Shift Registers https://www.aliexpress.com/item/Free-Shipping-100pcs-Lot-74HC595D-74HC595-SOP16/32494277537.html
9 × 100 ohm Resistor Array (8 per IC for segment current limiting) http://www.digikey.com/product-detail/en/cts-resistor-products/766163101GP/766-163-R100P-ND/1114618
1 × 4x4 Membrane Keypad https://www.aliexpress.com/item/16-Key-4-x-4-Membrane-Switch-Keypad-4x4-4-4-Matrix-Array-Matrix-keyboard-for/32652378032.html
1 × 4k7 ohm resistor Keypad voltage divider
3 × 1k5 ohm resistor Keypad voltage divider
4 × 390 ohm resistor Keypad voltage divider
1 × 0.01 uF ceramic capacitor To debounce the keypad
1 × Arduino I used a Nano, but just about any Arduino should work
9 × 2N2222A NPN Transistor To drive the 9 columns
9 × 1K ohm resistor Between the Arduino Digital pin and the Base of the transistor