Emergency! Miss Snell is on a school trip and she needs to ring Mrs Redhead, but oh no! She's forgotten her password and been locked out of her phone! Can year 4 help? 

Year 4 were told that the only digits in passcode were 0 and 1, so they needed to use trial and error to work out how many possible combinations there were! Year 4 managed to find the 14 different combinations quite quickly so we made the challenge harder! Now the passcode had 3 different digits, 0, 1 and 2! Immediately we agreed that by increasing the number of digits the number of possible combinations would also increas! Some of the children used strategies, and tried to set their working out in columns to make it easier! Some children just guessed random numbers, but during our discussion we realised this wasn't an efficient strategy to solve the problem. Year 4 demonstarted some brilliant problem solving skills today, and luckily Miss Snell managed to crack the code and unlock her phone!