Always check the pin-outs of the TTL chips before wiring up your circuit.
74LS00: Quad 2-Input NAND Gates
74LS02: Quad 2-Input NOR Gates
74LS04: Hex INVERTERs
74LS08: Quad 2-Input AND Gates
74LS10: Triple 3-Input NAND Gates
74LS20: Dual 4-Input NAND Gates
74LS27: Triple 3-Input NOR Gates
74LS30: Single 8-Input NAND Gate
74LS32: Quad 2-Input OR Gates
74LS47: BCD-To-Seven-Segment Decoder/Driver
74LS74: Dual Positive Edge-Triggered D Flip-Flops
74LS76: Dual Positive Edge-Triggered JK Flip-Flops
74LS86: Quad 2-Input XOR Gates
74LS109: Dual Positive Edge-Triggered JK' Flip-Flops
74LS138: 3-to-8 Decoder
74LS151: 8-to-1 Multiplexer (Data Selector)
74LS168: Synchronous 4-Bit BCD Up/Down Counter
74LS192: Synchronous 4-Bit BCD Up/Down Counter