Factors, multiples and primes: online calculators

A prime factorisation calculator:

http://www.mathwarehouse.com/arithmetic/numbers/prime-number/prime-factorization-calculator.php

Murderous Maths has an HCF/LCM calculator:

http://www.murderousmaths.co.uk/books/bkmm4xlc.htm

Quick response codes

Make a treasure hunt, provide a link to extension work, and more using QR codes:

http://teachery.net/how-teachers-can-use-qr-codes/

Random name picker

From Classtools, this nifty device allows you to input a class list and then choose a name at random.

http://www.classtools.net/education-games-php/fruit_machine