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.
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?
What is the largest number you can make using the three digits 2, 3 and 4 in any way you like, using any operations you like? You can only use each digit once.
If the odd numbers on two dice are made negative, which of the totals cannot be achieved?
If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?
Weekly Problem 49 - 2013
What is the value of 2000 + 1999 × 2000?
What is the value of c in this subtraction?
Tony and Tina can't work out which of them owes what to the other. Can you?
How many of the numbers 1 to 20 are not the sum of two primes?
