Python 3, 138 bytes

Easy translation of the interpreter language instructions:

for i in[len(o)/11for o in input().split(' ')]:
 if i==1:a=0
 if i==2:a=a+1
 if i==3:a=a-1
 if i==4:a=a*2
 if i==5:a=a/2
 if i==6:print(a)

Try it online!

In the first line:

1. takes the input
2. split the instructions separated by a space
3. divide by 11 (the lenght of the base word interpreter) to get the corresponding operation

The subsequent if execute the operations on the accumulator.

EDIT: theoretical improvements, code not modified (see version 2). Anyway, thanks for the suggestions!

-4 bytes thanks to @expressjs123

-3 bytes thanks to @ElPedro

VERSION 2

Python 3, 97 96 bytes

Improved the selection of the instructions simply by using list slicing.

-41 bytes compared to original version.

-1 byte thanks to @ElPedro

a=0
for i in[len(o)//11for o in input().split()]:
 a=[0,a+1,a-1,a*2,a/2,a][i-1]
 if i>5:print(a)

Try it online!

Python 3, 138 bytes

Easy translation of the interpreter language instructions:

for i in[len(o)/11for o in input().split(' ')]:
 if i==1:a=0
 if i==2:a=a+1
 if i==3:a=a-1
 if i==4:a=a*2
 if i==5:a=a/2
 if i==6:print(a)

Try it online!

In the first line:

1. takes the input
2. split the instructions separated by a space
3. divide by 11 (the lenght of the base word interpreter) to get the corresponding operation

The subsequent if execute the operations on the accumulator.

EDIT: theoretical improvements, code not modified (see version 2). Anyway, thanks for the suggestions!

-4 bytes thanks to @expressjs123

-3 bytes thanks to @ElPedro

VERSION 2

Python 3, 97 96 93 bytes

Improved the selection of the instructions simply by using list slicing.

-41 bytes compared to original version.

-1 byte thanks to @ElPedro

-3 bytes thanks to @Zaelin Goodman

a=0
for i in[len(o)//11for o in input().split()]:
 a-=[a,-1,1,-a,a/2,0][i-1]
 if i>5:print(a)

Try it online!

Python 3, 138 bytes

Easy translation of the interpreter language instructions:

for i in[len(o)/11for o in input().split(' ')]:
 if i==1:a=0
 if i==2:a=a+1
 if i==3:a=a-1
 if i==4:a=a*2
 if i==5:a=a/2
 if i==6:print(a)

Try it online!

In the first line:

1. takes the input
2. split the instructions separated by a space
3. divide by 11 (the lenght of the base word interpreter) to get the corresponding operation

The subsequent if execute the operations on the accumulator.

EDIT: theoretical improvements, code not modified (see version 2). Anyway, thanks for the suggestions!

-4 bytes thanks to @expressjs123

-3 bytes thanks to @ElPedro

VERSION 2

Python 3, 97 bytes

Improved the selection of the instructions simply by using list slicing.

-41 bytes compared to original version.

a=0
for i in[len(o)//11for o in input().split()]:
 a=[0,a+1,a-1,a*2,a/2,a][i-1]
 if i==6:print(a)

Try it online!

Python 3, 138 bytes

Easy translation of the interpreter language instructions:

for i in[len(o)/11for o in input().split(' ')]:
 if i==1:a=0
 if i==2:a=a+1
 if i==3:a=a-1
 if i==4:a=a*2
 if i==5:a=a/2
 if i==6:print(a)

Try it online!

In the first line:

1. takes the input
2. split the instructions separated by a space
3. divide by 11 (the lenght of the base word interpreter) to get the corresponding operation

The subsequent if execute the operations on the accumulator.

EDIT: theoretical improvements, code not modified (see version 2). Anyway, thanks for the suggestions!

-4 bytes thanks to @expressjs123

-3 bytes thanks to @ElPedro

VERSION 2

Python 3, 97 96 bytes

Improved the selection of the instructions simply by using list slicing.

-41 bytes compared to original version.

-1 byte thanks to @ElPedro

a=0
for i in[len(o)//11for o in input().split()]:
 a=[0,a+1,a-1,a*2,a/2,a][i-1]
 if i>5:print(a)

Try it online!

Python 3, 138 bytes

Easy translation of the interpreter language instructions:

for i in[len(o)/11for o in input().split(' ')]:
 if i==1:a=0
 if i==2:a=a+1
 if i==3:a=a-1
 if i==4:a=a*2
 if i==5:a=a/2
 if i==6:print(a)

Try it online!

In the first line:

1. takes the input
2. split the instructions separated by a space
3. divide by 11 (the lenght of the base word interpreter) to get the corresponding operation

The subsequent if execute the operations on the accumulator.

Python 3, 138 bytes

Easy translation of the interpreter language instructions:

for i in[len(o)/11for o in input().split(' ')]:
 if i==1:a=0
 if i==2:a=a+1
 if i==3:a=a-1
 if i==4:a=a*2
 if i==5:a=a/2
 if i==6:print(a)

Try it online!

In the first line:

1. takes the input
2. split the instructions separated by a space
3. divide by 11 (the lenght of the base word interpreter) to get the corresponding operation

The subsequent if execute the operations on the accumulator.

EDIT: theoretical improvements, code not modified (see version 2). Anyway, thanks for the suggestions!

-4 bytes thanks to @expressjs123

-3 bytes thanks to @ElPedro

VERSION 2

Python 3, 97 bytes

Improved the selection of the instructions simply by using list slicing.

-41 bytes compared to original version.

a=0
for i in[len(o)//11for o in input().split()]:
 a=[0,a+1,a-1,a*2,a/2,a][i-1]
 if i==6:print(a)

Try it online!