# Part1 - calculator

	.data

#strings for retrieving information and returning result.
prompt1:	.asciiz "\nEnter first number\n"
prompt2:	.asciiz "Enter second number\n"
operator:	.asciiz "Enter operation\n"
outmsg:		.asciiz "\nThe result is:\n"

	.globl main

	.text

main:
	# prompt for first number
	li $v0, 4
	la $a0, prompt1
	syscall

	# get number
	li $v0, 5
	syscall

	# move number to $s0. $v0 will be reused.
	add $s0, $zero, $v0

	# prompt for second number
	li $v0, 4
	la $a0, prompt2
	syscall

	li $v0, 5
	syscall

    # move 2nd number to $s1
	add $s1, $zero, $v0

	# prompt for operator
	li $v0, 4
	la $a0, operator
	syscall

	# get operator
	li $v0, 12
	syscall

	# keep operator code in $s2
	add $s2, $zero, $v0

	# output message
	li $v0, 4
	la $a0, outmsg
	syscall

	# Multi-if-then per expected operator
	li  $t0, '+'
	beq $s2, $t0, addt

	li  $t0, '-'
	beq $s2, $t0, subt

	li  $t0, '*'
	beq $s2, $t0, multi

	li  $t0, '/'
	beq $s2, $t0, divi

	# Wrong/unknown operation
	j  exit

addt:
	add $t0, $s0, $s1 
	j print

subt:
	sub $t0, $s0, $s1
	j print
	
multi:
	mult $s0, $s1
	mflo $t0 # keep the low part of product
	j print

divi:
	div $s0, $s1
	mflo $t0   #keep quotient
	j print

print:
	li   $v0, 1
    add  $a0, $zero, $t0
    syscall     

exit:
	li   $v0, 10
    syscall