### NRICH PROBLEM SOLVING PLACE VALUE

Subtraction Surprise Age 7 to 14 Challenge Level: All 5 to 11 7 to 14 11 to 16 14 to 18 Challenge level: This is a game in which your counters move in a spiral round the snail’s shell. Can you explain your findings? Can you replace the letters with numbers?

Each of the different letters stands for a different number. Lee was writing all the counting numbers from 1 to Becky created a number plumber which multiplies by 5 and subtracts 4. Have a go at balancing this equation. What is the minimum number of small cards that is needed? Can you build it up? Number problems at primary level to work on with others.

## Place Value, Integers, Ordering & Rounding

Alien Counting Nriich 7 to 11 Challenge Level: Legs Eleven Age 11 to 14 Challenge Level: Is there only one solution in each case? There are six numbers written in five different scripts. Diagonal Sums Age 7 to 11 Challenge Level: Can you explain your findings?

What is the minimum number of small cards that is needed? What is the smallest number you can find that lights up all the lights?

# Place Value, Integers, Ordering & Rounding :

Can you choose sets of numbers to collect so that you spin six numbers belonging to your sets in as few spins as possible? Magic Vs Age 7 to 11 Challenge Level: This article suggests some ways of making sense of calculations involving positive and negative numbers. Use two dice to generate two numbers with one decimal place. Can you reduce this to 7 using just the 7 key and add, solcing, multiply, divide and equals as many times as you like?

Are you surprised by the results? A Pllace about Absolutely Nothing Age 7 to 18 This article for the young and old talks about the origins of our number system and the important role zero has to play in it.

## Place Value and Powers

Number problems for inquiring primary learners. When this 2-digit number is reversed and squared, the difference between the squares is also a square.

What happens when you round these three-digit numbers to the nearest ? In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks.

Two Spinners Age 5 to 7 Challenge Level: Number problems at primary level to work on with others. Dicey Operations Age 11 to 14 Challenge Level: Add to Age 11 to 14 Challenge Level: How many solutions can you find to this sum? Multiply Multiples 3 Age 7 to 11 Challenge Level: Have a go at balancing this equation.

Each child in Class 3 took four numbers out of the bag. How would you test your idea? Try out this number trick. What do you notice about the numbers that it produces?

A random digit is generated. Can you find different ways of doing it?

This article, written for teachers, looks at the different kinds of recordings encountered in Primary Mathematics lessons and the importance of not jumping to conclusions! Find the sum of all three-digit numbers each of whose digits is odd. Visualisation and the development of number sense with kindergarten children. These short problems can vlue used to test your students’ understanding of place value. To support this aim, members of the Solvnig team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.