Dicey Operations for an adult and child. Can you get close to 1000 than your partner?
Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.
A game to be played against the computer, or in groups. Pick a 7-digit number. A random digit is generated. What must you subract to remove the digit from your number? the first to zero wins.
Who said that adding couldn't be fun?
Number problems for inquiring primary learners.
Replace the letters with numbers to make the addition work out correctly. R E A D + T H I S = P A G E
Number problems at primary level that require careful consideration.
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?
Each child in Class 3 took four numbers out of the bag. Who had made the highest even number?
The letters in the following addition sum represent the digits 1 ... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
How many solutions can you find to this sum? Each of the different letters stands for a different number.
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.
Find the values of the nine letters in the sum: FOOT + BALL = GAME
Consider all of the five digit numbers which we can form using only the digits 2, 4, 6 and 8. If these numbers are arranged in ascending order, what is the 512th number?
There are six numbers written in five different scripts. Can you sort out which is which?
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?
Can you work out some different ways to balance this equation?
Can you replace the letters with numbers? Is there only one solution in each case?
Have a go at balancing this equation. Can you find different ways of doing it?
What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?
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?
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
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?
A school song book contains 700 songs. The numbers of the songs are displayed by combining special small single-digit cards. What is the minimum number of small cards that is needed?
This multiplication uses each of the digits 0 - 9 once and once only. Using the information given, can you replace the stars in the calculation with figures?
Pick the number of times a week that you eat chocolate. This number must be more than one but less than ten. Multiply this number by 2. Add 5 (for Sunday). Multiply by 50... Can you explain why it. . . .
Find the sum of all three-digit numbers each of whose digits is odd.
In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks. Can you reconstruct the original multiplication?
What happens when you round these three-digit numbers to the nearest 100?
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?
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
Can you substitute numbers for the letters in these sums?
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
How many six digit numbers are there which DO NOT contain a 5?
Number problems at primary level to work on with others.
Number problems at primary level that may require resilience.
What is the sum of all the digits in all the integers from one to one million?
A three digit number abc is always divisible by 7 when 2a+3b+c is divisible by 7. Why?
Using balancing scales what is the least number of weights needed to weigh all integer masses from 1 to 1000? Placing some of the weights in the same pan as the object how many are needed?
Follow the clues to find the mystery number.
Replace each letter with a digit to make this addition correct.
Use two dice to generate two numbers with one decimal place. What happens when you round these numbers to the nearest whole number?
When the number x 1 x x x is multiplied by 417 this gives the answer 9 x x x 0 5 7. Find the missing digits, each of which is represented by an "x" .
The number 3723(in base 10) is written as 123 in another base. What is that base?
This addition sum uses all ten digits 0, 1, 2...9 exactly once. Find the sum and show that the one you give is the only possibility.
Consider all two digit numbers (10, 11, . . . ,99). In writing down all these numbers, which digits occur least often, and which occur most often ? What about three digit numbers, four digit numbers. . . .
What happens when you round these numbers to the nearest whole number?
Investigate the different ways these aliens count in this challenge. You could start by thinking about how each of them would write our number 7.
Try out some calculations. Are you surprised by the results?
Can you arrange the digits 1,2,3,4,5,6,7,8,9 into three 3-digit numbers such that their total is close to 1500?