finally found it !! I SHOULD HAVE ALSO stated -- take from the TOP -- today's high 3154.90√ = 56.1684965 - 0.25 = 55.9184965 *2 = 3126.87825 = close to today's day low of 3127.12  see how EASY it is when squaring √ price then add/subtract integers / fractions, etc.  $SPX