How can you use just one weighing to find out which box contains
the lighter ten coins out of the ten boxes?
Pat counts her sweets in different groups and both times she has
some left over. How many sweets could she have had?
Norrie sees two lights flash at the same time, then one of them
flashes every 4th second, and the other flashes every 5th second.
How many times do they flash together during a whole minute?
Can you place the numbers from 1 to 10 in the grid?
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
Can you work out what a ziffle is on the planet Zargon?
You can make a calculator count for you by any number you choose.
You can count by ones to reach 24. You can count by twos to reach
24. What else can you count by to reach 24?
Becky created a number plumber which multiplies by 5 and subtracts
4. What do you notice about the numbers that it produces? Can you
explain your findings?
What is the lowest number which always leaves a remainder of 1 when
divided by each of the numbers from 2 to 10?
Work out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'.
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
Four of these clues are needed to find the chosen number on this
grid and four are true but do nothing to help in finding the
number. Can you sort out the clues and find the number?
56 406 is the product of two consecutive numbers. What are these
If there is a ring of six chairs and thirty children must either
sit on a chair or stand behind one, how many children will be
behind each chair?
Use this grid to shade the numbers in the way described. Which
numbers do you have left? Do you know what they are called?
Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?
Can you find the chosen number from the grid using the clues?
Look at the squares in this problem. What does the next square look
like? I draw a square with 81 little squares inside it. How long
and how wide is my square?
This activity focuses on doubling multiples of five.
Can you complete this jigsaw of the multiplication square?
Katie and Will have some balloons. Will's balloon burst at exactly
the same size as Katie's at the beginning of a puff. How many puffs
had Will done before his balloon burst?
Find the words hidden inside each of the circles by counting around
a certain number of spaces to find each letter in turn.
The planet of Vuvv has seven moons. Can you work out how long it is
between each super-eclipse?
If you have only four weights, where could you place them in order
to balance this equaliser?
Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. How many lollies could there have been in the bag?
These red, yellow and blue spinners were each spun 45 times in
total. Can you work out which numbers are on each spinner?
Andrew decorated 20 biscuits to take to a party. He lined them up and put icing on every second biscuit and different decorations on other biscuits. How many biscuits weren't decorated?
Find the squares that Froggie skips onto to get to the pumpkin patch. She starts on 3 and finishes on 30, but she lands only on a square that has a number 3 more than the square she skips from.
Use the interactivities to complete these Venn diagrams.
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
I am thinking of three sets of numbers less than 101. Can you find
all the numbers in each set from these clues?
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.
Does a graph of the triangular numbers cross a graph of the six
times table? If so, where? Will a graph of the square numbers cross
the times table too?
In this maze of hexagons, you start in the centre at 0. The next
hexagon must be a multiple of 2 and the next a multiple of 5. What
are the possible paths you could take?
Follow the clues to find the mystery number.
This article for teachers describes how number arrays can be a
useful reprentation for many number concepts.
Four of these clues are needed to find the chosen number on this grid and four are true but do nothing to help in finding the number. Can you sort out the clues and find the number?
Help share out the biscuits the children have made.
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.
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?
I am thinking of three sets of numbers less than 101. They are the
red set, the green set and the blue set. Can you find all the
numbers in the sets from these clues?
Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?
Is it possible to draw a 5-pointed star without taking your pencil
off the paper? Is it possible to draw a 6-pointed star in the same
way without taking your pen off?
Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?
Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?
There are ten children in Becky's group. Can you find a set of
numbers for each of them? Are there any other sets?
Are these domino games fair? Can you explain why or why not?
How many trains can you make which are the same length as Matt's, using rods that are identical?
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?