problem
What is Ziffle?
Age
7 to 11
Challenge level
Can you work out what a ziffle is on the planet Zargon?
problem
Abundant Numbers
Age
7 to 11
Challenge level
48 is called an abundant number because it is less than the sum of its factors (without itself). Can you find some more abundant numbers?
problem
Make 100
Age
7 to 11
Challenge level
Find at least one way to put in some operation signs to make these digits come to 100.
problem
Factor Lines
Age
7 to 14
Challenge level
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
problem
Which is quicker?
Age
7 to 11
Challenge level
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?