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There are **52** NRICH Mathematical resources connected to **Mental calculations**, you may find related items under Calculations and numerical methods.

Problem
Primary curriculum
Secondary curriculum
### 5 by 5 Mathdokus

Can you use the clues to complete these 5 by 5 Mathematical Sudokus?

Age 7 to 16

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### 4 by 4 Mathdokus

Can you use the clues to complete these 4 by 4 Mathematical Sudokus?

Age 7 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Subtraction Slip

Can you spot the mistake in this video? How would you work out the answer to this calculation?

Age 5 to 7

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Compare the Calculations

Can you put these four calculations into order of difficulty? How did you decide?

Age 7 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Picture Your Method

Can you match these calculation methods to their visual representations?

Age 7 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Fruity Pairs

Which two items of fruit could Kate and Sam choose? Can you order the prices from lowest to highest?

Age 5 to 7

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Arranging Additions and Sorting Subtractions

Order these four calculations from easiest to hardest. How did you decide?

Age 5 to 7

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Can You Make 100?

How many ways can you find to put in operation signs (+, −, ×, ÷) to make 100?

Age 11 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Overlaps

Can you find ways to put numbers in the overlaps so the rings have equal totals?

Age 11 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Missing Multipliers

What is the smallest number of answers you need to reveal in order to work out the missing headers?

Age 7 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### How Do You Do It?

This group activity will encourage you to share calculation strategies and to think about which strategy might be the most efficient.

Age 7 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Going Round in Circles

Mathematicians are always looking for efficient methods for solving problems. How efficient can you be?

Age 11 to 14

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Dicey Operations

Who said that adding, subtracting, multiplying and dividing couldn't be fun?

Age 11 to 14

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Countdown

Here is a chance to play a version of the classic Countdown Game.

Age 7 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Power Countdown

In this twist on the well-known Countdown numbers game, use your knowledge of Powers and Roots to make a target.

Age 14 to 16

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Difference Sudoku

Use the differences to find the solution to this Sudoku.

Age 14 to 16

Challenge Level

General
Primary curriculum
Secondary curriculum
### Integrated Sums Sudoku

The puzzle can be solved with the help of small clue-numbers which are either placed on the border lines between selected pairs of neighbouring squares of the grid or placed after slash marks on the intersections between two diagonally adjacent squares.

Age 11 to 16

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Consecutive Seven

Can you arrange these numbers into 7 subsets, each of three numbers, so that when the numbers in each are added together, they make seven consecutive numbers?

Age 11 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Mind Reading

Think of a number, add one, double it, take away 3, add the number you first thought of, add 7, divide by 3 and take away the number you first thought of. You should now be left with 2. How do I know?

Age 11 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Multiplication Tables - Matching Cards

Practise your tables skills and try to beat your previous best score in this interactive game.

Age 5 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Shapes on the Playground

Sally and Ben were drawing shapes in chalk on the school playground. Can you work out what shapes each of them drew using the clues?

Age 7 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Where Can We Visit?

Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?

Age 11 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Days and Dates

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

Age 11 to 14

Challenge Level

Article
Primary curriculum
Secondary curriculum
### Let's Get Flexible!

In this article for primary teachers, Ems outlines how we can encourage learners to be flexible in their approach to calculation, and why this is crucial.

Age 5 to 11

List
Primary curriculum
Secondary curriculum
### Being Curious - Primary Number

Number problems for inquiring primary learners.

Age 5 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Dicey Operations in Line for Two

Dicey Operations for an adult and child. Can you get close to 1000 than your partner?

Age 7 to 11

Challenge Level

List
Primary curriculum
Secondary curriculum
### More Playing with Number Upper Primary

Related resources supporting pupils' understanding of multiplication and division through playing with numbers.

Age 7 to 11

List
Primary curriculum
Secondary curriculum
### Current Playing with Number Upper Primary Teacher

Resources to support understanding of multiplication and division through playing with number.

Age 7 to 11

Challenge Level

List
Primary curriculum
Secondary curriculum
### More Playing with Number Lower Primary

Some additional activities to develop children's understanding of addition and subtraction of number through playing with number.

Age 5 to 7

List
Primary curriculum
Secondary curriculum
### More Playing with Numbers Upper Primary

More resources to support understanding multiplication and division through playing with numbers

Age 7 to 11

Problem
Primary curriculum
Secondary curriculum
### Mathdoku

Complete the Mathdoku grid using the clues. Can you convince us that the number you have chosen for each square has to be correct?

Age 7 to 11

Challenge Level

Article
Primary curriculum
Secondary curriculum
### Clever Carl

What would you do if your teacher asked you add all the numbers from 1 to 100? Find out how Carl Gauss responded when he was asked to do just that.

Age 7 to 14

Problem
Primary curriculum
Secondary curriculum
### Chocoholics

George and Jim want to buy a chocolate bar. George needs 2p more and Jim need 50p more to buy it. How much is the chocolate bar?

Age 7 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Transformations Tables

These grids are filled according to some rules - can you complete them?

Age 7 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Calculator Bingo

This is a game for two players. What must you subtract to remove the rolled digit from your number? The first to zero wins!

Age 7 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Wild Jack

A game for 2 or more players with a pack of cards. Practise your skills of addition, subtraction, multiplication and division to hit the target score.

Age 7 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Criss Cross Quiz

A game for 2 players. Practises subtraction or other maths operations knowledge.

Age 7 to 11

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Flip Flop - Matching Cards

Practise your number bonds whilst improving your memory in this matching pairs game.

Age 5 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Subtraction Squares

A game for 2 players. Using 2 dice, some counters and a games board, can you form a line of counters from one side of the board to the other?

Age 5 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Pass the Peas, Please

A game for 2 or more players. Practise your addition and subtraction with the aid of a game board and some dried peas!

Age 5 to 7

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Down to Nothing

A game for 2 or more people. Starting with 100, subratct a number from 1 to 9 from the total. You score for making an odd number, a number ending in 0 or a multiple of 6.

Age 7 to 11

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Fifteen

Can you spot the similarities between this game and other games you know? The aim is to choose 3 numbers that total 15.

Age 7 to 14

Challenge Level

Game
Primary curriculum
Secondary curriculum
### Domino Magic Rectangle

An ordinary set of dominoes can be laid out as a 7 by 4 magic rectangle in which all the spots in all the columns add to 24, while those in the rows add to 42. Try it! Now try the magic square...

Age 7 to 16

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Is it Magic or Is it Maths?

Here are three 'tricks' to amaze your friends. But the really clever trick is explaining to them why these 'tricks' are maths not magic. Like all good magicians, you should practice by trying them. Can you explain how they work?

Age 11 to 14

Challenge Level

Problem
Primary curriculum
Secondary curriculum
### Prime Magic

Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?

Age 7 to 16

Challenge Level