Assembly: String Input (word size) and Re-printing

Question

I don't know what went wrong. I want to input string in WORD size and add a integer to the inputted value of string and reprint the results. I'm not really sure in the arithmetic operations since this is my first time in using many operations in a single program and they are in 16 bits.

clr macro  
mov ax, 03h  
int 10h  
endm  

cseg segment para 'code'  
assume cs:cseg; ds:cseg; ss:cseg; es:cseg  
org 100h  

start: jmp begin  

amount_s label word  
amount_max dw 3  
amount_length dw ?  
amount_field dw 3 dup (?)  

x1 dw 0  
x2 dw 0  

sum1 dw 0
sum2 dw 0

bal dw 10

begin:  clr

mov ah, 0Ah     ;input string
lea dx, amount_s
mov cx, amount_length
lea si, amount_field
int 21h

mov ax, [si]        ;copy si to ax
sub ax, 30h     ;converts value of ax to integer
mov bx, 10      ;copy 10 to bx      
mul bx          ;multiply it ax by bx
mov x1, ax      ; copy ax to x1
inc si          ;move si pointer by 1

mov ax, [si]        ;copy si to ax
sub ax, 30h     ;converts value of ax to integer
mov x2, ax      ; copy ax to x2

add ax, x1      ;add ax which is x2 by x1
add ax, bal     ; add ax by bal which is 10
mov sum1, ax        ;copy the result to sum1

mov dx, 0       ; copy 0 to dx  
mov bx, 10      ; copy 10 to bx
div bx          ;divides ax by bx
mov sum1, ax        ; copy quotient to sum1
mov sum2, dx        ; copy remainder to sum2

add sum1, 30h       ;convert for printing
add sum2, 30h       ;convert for printing

mov ah, 02h     ;prints sum1
mov dx, sum1
int 21h

mov ah, 02h     ;prints sum2
mov dx, sum2
int 21h

int 20h
cseg ends
end start

Answer 1

How about debugging and checking reference documentation to see what goes wrong and how? :)

One thing I can tell outright, the structure that the function 0ah of int 21h uses contains byte fields, not word fields.

And yet you declare them as words (dw), not bytes (db):

amount_max dw 3
amount_length dw ?
amount_field dw 3 dup (?)

And you shouldn't be accessing them as words as you do with:

mov ax, [si]

Instead, read bytes:

mov al, [si]

And if you want to convert byte values into word values, just stick a 0 into the top byte of the word register like so:

mov ah, 0

The rest looks reasonable, but I have not run the code. You should do it. In a debugger, if it's not working right.