# Resources tagged with: Mental calculation strategies

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### There are 21 results

Broad Topics > Calculations and Numerical Methods > Mental calculation strategies

### Integrated Sums Sudoku

##### Age 11 to 16Challenge Level

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. . . .

### Intersection Sums Sudoku

##### Age 7 to 16Challenge Level

A Sudoku with clues given as sums of entries.

### Bochap Sudoku

##### Age 11 to 16Challenge Level

This Sudoku combines all four arithmetic operations.

### Countdown

##### Age 7 to 14Challenge Level

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

### Fifteen

##### Age 7 to 14Challenge Level

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

### Difference Sudoku

##### Age 14 to 16Challenge Level

Use the differences to find the solution to this Sudoku.

### Dicey Operations

##### Age 11 to 14Challenge Level

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

### Can You Make 100?

##### Age 11 to 14Challenge Level

How many ways can you find to put in operation signs (+ - x รท) to make 100?

##### Age 11 to 14Challenge Level

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. . . .

### Clever Carl

##### Age 7 to 14

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.

### Consecutive Seven

##### Age 11 to 14Challenge Level

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?

### Missing Multipliers

##### Age 7 to 14Challenge Level

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

### Going Round in Circles

##### Age 11 to 14Challenge Level

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

### Prime Magic

##### Age 7 to 16Challenge Level

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?

### Domino Magic Rectangle

##### Age 7 to 16Challenge Level

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...

### Is it Magic or Is it Maths?

##### Age 11 to 14Challenge Level

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. . . .

### Days and Dates

##### Age 11 to 14Challenge Level

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

### Thousands and Millions

##### Age 11 to 14Challenge Level

Here's a chance to work with large numbers...

### Overlaps

##### Age 11 to 14Challenge Level

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

### Power Countdown

##### Age 14 to 16Challenge Level

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