$base = DB::table('questions')->where('qa_status','needs_revision');
$cnt = function($needle) {
  return DB::table('questions')->where('qa_status','needs_revision')->where('question','like','%'.$needle.'%')->count();
};
echo "needs_revision TOTAL: ".$base->count()."\n";
echo "contains 'frac{1}{2}': ".$cnt('frac{1}{2}')."\n";
echo "contains '\\frac':      ".$cnt('\\frac')."\n";
echo "contains 'frac':        ".$cnt('frac')."\n";
echo "contains half-char :    ".$cnt('½')."\n";
echo "contains '1/2':         ".$cnt('1/2')."\n";
echo "contains '1}{2}':       ".$cnt('1}{2}')."\n";
echo "contains '/':           ".$cnt('/')."\n";
echo "contains '\$\$':          ".$cnt('$$')."\n";
echo "contains '\\(':          ".$cnt('\\(')."\n";
echo "--- 18 samples (id | source | first 110 chars) ---\n";
foreach ($base->orderBy('id')->limit(18)->get(['id','source','question']) as $r) {
  echo "#".$r->id." [".($r->source ?? '-')."]: ".substr(preg_replace('/\s+/',' ',(string)$r->question),0,110)."\n";
}