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Primary live problems and recent solutions

Each time you visit the NRICH site there are usually some activities which are 'live'. This means we are inviting students to send us solutions, and we will publish a selection of them, along with each student's name and their school, a few weeks later. If you'd like to know more about what we're looking for, read this short article.

The last day for submitting solutions to these live problems is Monday 3 March.

Live problems

  • problem

    Pairs of numbers

    Age
    5 to 7
    Challenge level
    filled star empty star empty star

    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?

  • Name That Triangle!
    problem

    Name that triangle!

    Age
    7 to 11
    Challenge level
    filled star empty star empty star

    Can you sketch triangles that fit in the cells in this grid? Which ones are impossible? How do you know?

  • Compare the Calculations
    problem

    Compare the calculations

    Age
    7 to 11
    Challenge level
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    Can you put these four calculations into order of difficulty? How did you decide?

  • Times Tables Shifts
    problem

    Times tables shifts

    Age
    7 to 11
    Challenge level
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    In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

Recently solved problems

  • Take three numbers
    problem

    Take three numbers

    Age
    7 to 11
    Challenge level
    filled star empty star empty star

    What happens when you add three numbers together? Will your answer be odd or even? How do you know?

  • Holes
    problem

    Holes

    Age
    5 to 11
    Challenge level
    filled star empty star empty star

    I've made some cubes and some cubes with holes in. This challenge invites you to explore the difference in the number of small cubes I've used. Can you see any patterns?

  • Lots of Lollies
    problem

    Lots of lollies

    Age
    5 to 7
    Challenge level
    filled star filled star filled star

    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?

  • Round the Three Dice
    problem

    Round the three dice

    Age
    7 to 11
    Challenge level
    filled star empty star empty star

    What happens when you round these three-digit numbers to the nearest 100?