Exploring and noticing

There are 412 NRICH Mathematical resources connected to Exploring and noticing
Make 100
problem
Favourite

Make 100

Age
7 to 11
Challenge level
filled star filled star empty star
Find at least one way to put in some operation signs to make these digits come to 100.
One Wasn't Square
problem
Favourite

One wasn't square

Age
7 to 11
Challenge level
filled star filled star empty star
Mrs Morgan, the class's teacher, pinned numbers onto the backs of three children. Use the information to find out what the three numbers were.
Tiny Nines
problem
Favourite

Tiny nines

Age
14 to 16
Challenge level
filled star filled star empty star
What do you notice about these families of recurring decimals?
Complete the Square
problem
Favourite

Complete the square

Age
5 to 7
Challenge level
filled star filled star filled star

Complete the squares - but be warned some are trickier than they look!

Wallpaper
problem
Favourite

Wallpaper

Age
5 to 7
Challenge level
filled star filled star empty star

These pieces of wallpaper need to be ordered from smallest to largest. Can you find a way to do it?

Growing Garlic
problem
Favourite

Growing garlic

Age
5 to 11
Challenge level
filled star empty star empty star

Ben and his mum are planting garlic. Can you find out how many cloves of garlic they might have had?

Tug of War
problem
Favourite

Tug of war

Age
5 to 7
Challenge level
filled star empty star empty star

Can you use the numbers on the dice to reach your end of the number line before your partner beats you?

Elevenses
problem
Favourite

Elevenses

Age
11 to 14
Challenge level
filled star empty star empty star
How many pairs of numbers can you find that add up to a multiple of 11? Do you notice anything interesting about your results?
Sort them out (1)
problem
Favourite

Sort them out (1)

Age
5 to 7
Challenge level
filled star empty star empty star
Can you each work out the number on your card? What do you notice? How could you sort the cards?
Triple Cubes
problem
Favourite

Triple cubes

Age
5 to 11
Challenge level
filled star empty star empty star

This challenge involves eight three-cube models made from interlocking cubes. Investigate different ways of putting the models together then compare your constructions.