game
Odds and threes
A game for 2 people using a pack of cards Turn over 2 cards and try to make an odd number or a multiple of 3.
Odd and even numbers
problem
What number?
Age
5 to 7
Challenge level
I am less than 25. My ones digit is twice my tens digit. My digits add up to an even number.
problem
Crossings
Age
7 to 11
Challenge level
In this problem we are looking at sets of parallel sticks that
cross each other. What is the least number of crossings you can
make? And the greatest?
game
Down to nothing
A game for 2 or more people. Starting with 100, subratct a number from 1 to 9 from the total. You score for making an odd number, a number ending in 0 or a multiple of 6.
problem
Sets of numbers
Age
7 to 11
Challenge level
How many different sets of numbers with at least four members can you find in the numbers in this box?
problem
Cube bricks and daisy chains
Age
5 to 7
Challenge level
Daisy and Akram were making number patterns. Daisy was using beads that looked like flowers and Akram was using cube bricks. First they were counting in twos.
game
Part the piles
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
problem
Seven flipped
Age
7 to 11
Challenge level
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
problem
Numbers as shapes
Age
5 to 7
Challenge level
Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?
problem
Next-door numbers
Age
5 to 7
Challenge level
Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?