算术指令是执行基本算术运算(例如加法，减法等)的指令。在8085微处理器中，目标操作数通常是累加器。在8085微处理器中，目标操作数通常是累加器。
下表显示了算术指令列表：
| Opcode | Operand | Explanation | Example |
|---|---|---|---|
| ADD | R | A = A + R | ADD B |
| ADD | M | A = A + Mc | ADD 2050 |
| ADI | 8-bit data | A = A + 8-bit data | ADI 50 |
| ADC | R | A = A + R + prev. carry | ADC B |
| ADC | M | A = A + Mc + prev. carry | ADC 2050 |
| ACI | 8-bit data | A = A + 8-bit data + prev. carry | ACI 50 |
| SUB | R | A = A – R | SUB B |
| SUB | M | A = A – Mc | SUB 2050 |
| SUI | 8-bit data | A = A – 8-bit data | SUI 50 |
| SBB | R | A = A – R – prev. carry | SBB B |
| SBB | M | A = A – Mc -prev. carry | SBB 2050 |
| SBI | 8-bit data | A = A – 8-bit data – prev. carry | SBI 50 |
| INR | R | R = R + 1 | INR B |
| INR | M | M = Mc + 1 | INR 2050 |
| INX | r.p. | r.p. = r.p. + 1 | INX H |
| DCR | R | R = R – 1 | DCR B |
| DCR | M | M = Mc – 1 | DCR 2050 |
| DCX | r.p. | r.p. = r.p. – 1 | DCX H |
| DAD | r.p. | HL = HL + r.p. | DAD H |
在桌子上
R代表注册
M代表记忆
Mc代表记忆内容
rp代表寄存器对