Can you each work out the number on your card? What do you notice?
How could you sort the cards?
This project challenges you to work out the number of cubes hidden under a cloth. What questions would you like to ask?
Make your own double-sided magic square. But can you complete both
sides once you've made the pieces?
If you have ten counters numbered 1 to 10, how many can you put into pairs that add to 10? Which ones do you have to leave out? Why?
Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?
Explore Alex's number plumber. What questions would you like to ask? Don't forget to keep visiting NRICH projects site for the latest developments and questions.
Can you find which shapes you need to put into the grid to make the
totals at the end of each row and the bottom of each column?
Investigate this balance which is marked in halves. If you had a weight on the left-hand 7, where could you hang two weights on the right to make it balance?
Bernard Bagnall recommends some primary school problems which use
numbers from the environment around us, from clocks to house
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
Start by putting one million (1 000 000) into the display of your
calculator. Can you reduce this to 7 using just the 7 key and add,
subtract, multiply, divide and equals as many times as you like?
Use the information about Sally and her brother to find out how many children there are in the Brown family.
What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.
Can you use the information to find out which cards I have used?
Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
In a square in which the houses are evenly spaced, numbers 3 and 10
are opposite each other. What is the smallest and what is the
largest possible number of houses in the square?
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
Explore Alex's number plumber. What questions would you like to ask? What do you think is happening to the numbers?
Can you each work out the number on your card? What do you notice? How could you sort the cards?
There are to be 6 homes built on a new development site. They could
be semi-detached, detached or terraced houses. How many different
combinations of these can you find?
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
Are these statements always true, sometimes true or never true?
An old game but lots of arithmetic!
If you have only four weights, where could you place them in order
to balance this equaliser?
Can you make a cycle of pairs that add to make a square number
using all the numbers in the box below, once and once only?
Find your way through the grid starting at 2 and following these
operations. What number do you end on?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
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?
If the answer's 2010, what could the question be?
Ahmed is making rods using different numbers of cubes. Which rod is twice the length of his first rod?
Choose a symbol to put into the number sentence.
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
Can you hang weights in the right place to make the equaliser
This challenge extends the Plants investigation so now four or more children are involved.
Start with four numbers at the corners of a square and put the
total of two corners in the middle of that side. Keep going... Can
you estimate what the size of the last four numbers will be?
First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.
Investigate what happens when you add house numbers along a street
in different ways.
This challenging activity involves finding different ways to distribute fifteen items among four sets, when the sets must include three, four, five and six items.
Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!
Jack's mum bought some candles to use on his birthday cakes and when his sister was born, she used them on her cakes too. Can you use the information to find out when Kate was born?
In this section from a calendar, put a square box around the 1st,
2nd, 8th and 9th. Add all the pairs of numbers. What do you notice
about the answers?
Here you see the front and back views of a dodecahedron. Each
vertex has been numbered so that the numbers around each pentagonal
face add up to 65. Can you find all the missing numbers?
Are these statements relating to calculation and properties of shapes always true, sometimes true or never true?
Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
Shut the Box game for an adult and child. Can you turn over the cards which match the numbers on the dice?
Imagine a pyramid which is built in square layers of small cubes. If we number the cubes from the top, starting with 1, can you picture which cubes are directly below this first cube?
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
Investigate the different distances of these car journeys and find
out how long they take.