2462 /www/nrich/html/content/id/2462/ 1 2011-02-01T00:00:01 <?xml version="1.0" encoding="UTF-8"?> <mdoxml version="1.0"><br></br> I have some strange dice: the faces show the numbers 1 to 6 as usual, except that the odd numbers are negative (i.e. -1, -3, -5 in place of 1, 3, 5). If I throw two such dice, which of the following totals cannot be achieved?<br></br> <br></br> A) 3<br></br> <br></br> B) 7<br></br> <br></br> C) 8<br></br> <br></br> <br></br> <a href="http://nrich.maths.org/public/viewer.php?obj_id=6838&amp;part=">Clcik here for a poster of this problem</a>.<br></br>  <br></br> If you liked this problem, <a href="http://nrich.maths.org/53">here is an NRICH task</a> which challenges you to use similar mathematical ideas.  <br></br> <br></br></mdoxml> <?xml version="1.0" encoding="UTF-8"?> <mdoxml version="1.0">You cannot make 7.<br></br><br></br>3 = -1 + 4<br></br>8 = 4 + 4<br></br><br></br></mdoxml> 2 4 0 1 0 0 0 Weekly Problem 16 - 2012 Calculations and Numerical Methods Addition & subtraction Numbers and the Number System Positive-negative numbers Decision Mathematics and Combinatorics Combinations