Other tags that relate to Timing
Mass and weight. Angles - points, lines and parallel lines. Addition & subtraction. Speed and acceleration. Length/distance. Clock. Calendars. Temperature. Working systematically. Time.There are 227 results
Broad Topics > Calculations and Numerical Methods > Addition & subtraction
Watch the Clock
Age 7 to 11
Challenge Level
During the third hour after midnight the hands on a clock point in the same direction (so one hand is over the top of the other). At what time, to the nearest second, does this happen?
2010: A Year of Investigations
Age 5 to 14
This article for teachers suggests ideas for activities built around 10 and 2010.
Lengthy Journeys
Age 7 to 11
Challenge Level
Investigate the different distances of these car journeys and find out how long they take.
A Rod and a Pole
Age 7 to 11
Challenge Level
A lady has a steel rod and a wooden pole and she knows the length of each. How can she measure out an 8 unit piece of pole?
Times
Age 7 to 11
Challenge Level
Which times on a digital clock have a line of symmetry? Which look the same upside-down? You might like to try this investigation and find out!
Oranges and Lemons
Age 7 to 11
Challenge Level
On the table there is a pile of oranges and lemons that weighs exactly one kilogram. Using the information, can you work out how many lemons there are?
Numbers Numbers Everywhere!
Age 5 to 11
Bernard Bagnall recommends some primary school problems which use numbers from the environment around us, from clocks to house numbers.
Clocked
Age 11 to 14
Challenge Level
Is it possible to rearrange the numbers 1,2......12 around a clock face in such a way that every two numbers in adjacent positions differ by any of 3, 4 or 5 hours?
Clock Face
Age 7 to 11
Challenge Level
Where can you draw a line on a clock face so that the numbers on both sides have the same total?
Back to School
Age 7 to 11
Challenge Level
Mr. Sunshine tells the children they will have 2 hours of homework. After several calculations, Harry says he hasn't got time to do this homework. Can you see where his reasoning is wrong?
Consecutive Negative Numbers
Age 11 to 14
Challenge Level
Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?
Sheep Talk
Age 7 to 11
Challenge Level
In sheep talk the only letters used are B and A. A sequence of words is formed by following certain rules. What do you notice when you count the letters in each word?
Function Machines
Age 7 to 11
Challenge Level
If the numbers 5, 7 and 4 go into this function machine, what numbers will come out?
One Million to Seven
Age 7 to 11
Challenge Level
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?
Adding All Nine
Age 11 to 14
Challenge Level
Make a set of numbers that use all the digits from 1 to 9, once and once only. Add them up. The result is divisible by 9. Add each of the digits in the new number. What is their sum? Now try some. . . .
Carrying Cards
Age 7 to 11
Challenge Level
These sixteen children are standing in four lines of four, one behind the other. They are each holding a card with a number on it. Can you work out the missing numbers?
Diagonal Sums
Age 7 to 14
Challenge Level
In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?
The Money Maze
Age 7 to 11
Challenge Level
Go through the maze, collecting and losing your money as you go. Which route gives you the highest return? And the lowest?
Mobile Numbers
Age 5 to 11
Challenge Level
In this investigation, you are challenged to make mobile phone numbers which are easy to remember. What happens if you make a sequence adding 2 each time?
Number Differences
Age 7 to 11
Challenge Level
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?
Polo Square
Age 7 to 11
Challenge Level
Arrange eight of the numbers between 1 and 9 in the Polo Square below so that each side adds to the same total.
Oh! Harry!
Age 7 to 11
Challenge Level
A group of children are using measuring cylinders but they lose the labels. Can you help relabel them?
Dart Target
Age 7 to 11
Challenge Level
This task, written for the National Young Mathematicians' Award 2016, invites you to explore the different combinations of scores that you might get on these dart boards.
Rabbits in the Pen
Age 7 to 11
Challenge Level
Using the statements, can you work out how many of each type of rabbit there are in these pens?
The Twelve Pointed Star Game
Age 7 to 11
Challenge Level
Have a go at this game which involves throwing two dice and adding their totals. Where should you place your counters to be more likely to win?
Cows and Sheep
Age 7 to 11
Challenge Level
Use your logical reasoning to work out how many cows and how many sheep there are in each field.
Pole Star Sudoku 2
Age 11 to 16
Challenge Level
This Sudoku, based on differences. Using the one clue number can you find the solution?
Being Resilient - Primary Number
Age 5 to 11
Challenge Level
Number problems at primary level that may require resilience.
Weights
Age 11 to 14
Challenge Level
Different combinations of the weights available allow you to make different totals. Which totals can you make?
Asteroid Blast
Age 7 to 11
Challenge Level
A game for 2 people. Use your skills of addition, subtraction, multiplication and division to blast the asteroids.
Zargon Glasses
Age 7 to 11
Challenge Level
Zumf makes spectacles for the residents of the planet Zargon, who have either 3 eyes or 4 eyes. How many lenses will Zumf need to make all the different orders for 9 families?
Diagonal in a Spiral
Age 7 to 11
Challenge Level
Investigate the totals you get when adding numbers on the diagonal of this pattern in threes.
Hubble, Bubble
Age 7 to 11
Challenge Level
Winifred Wytsh bought a box each of jelly babies, milk jelly bears, yellow jelly bees and jelly belly beans. In how many different ways could she make a jolly jelly feast with 32 legs?
The Puzzling Sweet Shop
Age 5 to 11
Challenge Level
There were chews for 2p, mini eggs for 3p, Chocko bars for 5p and lollypops for 7p in the sweet shop. What could each of the children buy with their money?
The Pied Piper of Hamelin
Age 7 to 11
Challenge Level
This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!
One Wasn't Square
Age 7 to 11
Challenge Level
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.
Double Digit
Age 11 to 14
Challenge Level
Choose two digits and arrange them to make two double-digit numbers. Now add your double-digit numbers. Now add your single digit numbers. Divide your double-digit answer by your single-digit answer. . . .
Napier's Bones
Age 7 to 11
Challenge Level
The Scot, John Napier, invented these strips about 400 years ago to help calculate multiplication and division. Can you work out how to use Napier's bones to find the answer to these multiplications?
Penta Post
Age 7 to 11
Challenge Level
Here are the prices for 1st and 2nd class mail within the UK. You have an unlimited number of each of these stamps. Which stamps would you need to post a parcel weighing 825g?
Scoring with Dice
Age 7 to 11
Challenge Level
I throw three dice and get 5, 3 and 2. Add the scores on the three dice. What do you get? Now multiply the scores. What do you notice?
Street Sequences
Age 5 to 11
Challenge Level
Investigate what happens when you add house numbers along a street in different ways.
And So on and So On
Age 11 to 14
Challenge Level
If you wrote all the possible four digit numbers made by using each of the digits 2, 4, 5, 7 once, what would they add up to?
Got it Article
Age 7 to 14
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
Up, Down, Flying Around
Age 11 to 14
Challenge Level
Play this game to learn about adding and subtracting positive and negative numbers
Prompt Cards
Age 7 to 11
Challenge Level
These two group activities use mathematical reasoning - one is numerical, one geometric.
How Much Did it Cost?
Age 7 to 11
Challenge Level
Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.
NRICH is part of the family of activities in the Millennium Mathematics Project.