if else dividing in BASH [duplicate]

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• BASH Arithmetic Expressions 5 answers

I am doing a school assignment in bash and got this code:

if a < 0
    a = a/b
else
    a = b/a
fi

The assignment says that we need to divide two number read from the keyboard, and check if the first number is larger than the number 0.

echo "Write two numbers, with a space, that need to be divided:"
read a b
  if a > 0
    a = $a / $b
  else
    a = $b / $a
fi

echo "$a"

What am I doing wrong here?