Mental calculations

There are 106 NRICH Mathematical resources connected to Mental calculations
Six Numbered Cubes
problem
Favourite

Six numbered cubes

Age
7 to 11
Challenge level
filled star filled star empty star
This task combines spatial awareness with addition and multiplication.
Overlaps
problem
Favourite

Overlaps

Age
11 to 14
Challenge level
filled star filled star empty star
Can you find ways to put numbers in the overlaps so the rings have equal totals?
Double or Halve?
problem
Favourite

Double or halve?

Age
5 to 7
Challenge level
filled star empty star empty star
Throw the dice and decide whether to double or halve the number. Will you be the first to reach the target?
Difference Sudoku
problem
Favourite

Difference sudoku

Age
14 to 16
Challenge level
filled star filled star filled star
Use the differences to find the solution to this Sudoku.
Unit Differences
problem
Favourite

Unit differences

Age
5 to 7
Challenge level
filled star empty star empty star
This challenge is about finding the difference between numbers which have the same tens digit.
What Could \It Be?
problem
Favourite

What could it be?

Age
5 to 7
Challenge level
filled star empty star empty star
In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?
Multiply Multiples 3
problem
Favourite

Multiply multiples 3

Age
7 to 11
Challenge level
filled star empty star empty star
Have a go at balancing this equation. Can you find different ways of doing it?
Multiply Multiples 2
problem
Favourite

Multiply multiples 2

Age
7 to 11
Challenge level
filled star empty star empty star
Can you work out some different ways to balance this equation?
Multiply Multiples 1
problem
Favourite

Multiply multiples 1

Age
7 to 11
Challenge level
filled star empty star empty star
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
Play to 37
problem
Favourite

Play to 37

Age
7 to 11
Challenge level
filled star empty star empty star
In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.