Exploring and noticing

Can you match these calculations in Standard Index Form with their answers?

Is there a quick way to work out whether a fraction terminates or recurs when you write it as a decimal?

Try out this number trick. What happens with different starting numbers? What do you notice?

The Number Jumbler can always work out your chosen symbol. Can you work out how?

Throughout these challenges, the touching faces of any adjacent dice must have the same number. Can you find a way of making the total on the top come to each number from 11 to 18 inclusive?

Can you find examples of magic crosses? Can you find all the possibilities?

Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?

Edith had 9 children at 15 month intervals. If the oldest is now six times as old as the youngest, how old is her youngest child?

A pattern repeats every six symbols. What are the 100th and 101st symbols?

Weekly Problem 51 - 2016
Pegs numbered 1 to 50 are placed in a row. Alternate pegs are knocked down, and this process is repeated. What is the number of the last peg to be knocked down?