List

Equations and Formulae - Short Problems



This is part of our collection of Short Problems.

You may also be interested in our longer problems on Equations and Formulae  Age 11-14 and Age 14-16.

Printable worksheets containing selections of these problems are available here.

Partial Magic
problem

Partial Magic

Age
11 to 14
Challenge level
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This magic square has only been partially completed. Can you still solve it...
Interstellar
problem

Interstellar

Age
11 to 14
Challenge level
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What number could replace * so that */5 is between 3 and 4?
Seven Dwarfs
problem

Seven Dwarfs

Age
11 to 14
Challenge level
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The Seven Dwarfs have seven different birthdays. How old can they be?
Five-to
problem

Five-to

Age
11 to 14
Challenge level
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The number 2005 is the sum of a sequence of five consecutive positive integers. What is the smallest of these integers?
Luis' Eight
problem

Luis' Eight

Age
11 to 14
Challenge level
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Luis writes down eight consecutive positive integers. The sum of the three smallest numbers is 33. What is the sum of the three largest numbers?
Shape Sums
problem

Shape Sums

Age
11 to 14
Challenge level
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Given some relationships amongst these shapes, how many triangles equal one diamond?
Geometric Quadrilateral
problem

Geometric Quadrilateral

Age
11 to 14
Challenge level
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Each interior angle in a quadrilateral (apart from the smallest) is twice the previous one. What is the size of the smallest interior angle?
Multiplication Mistake
problem

Multiplication Mistake

Age
11 to 14
Challenge level
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Jane accidentally multiplied by 54 instead of 45, and her answer was 198 too big. What number did she multiply 54 by?
Turnips
problem

Turnips

Age
11 to 14
Challenge level
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Baldrick could buy 6 parsnips and 7 turnips, or 8 parsnips and 4 turnips. How many parsnips could he buy?
Star Sum
problem

Star Sum

Age
11 to 14
Challenge level
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You may have seen magic squares before, but can you work out the missing numbers on this magic star?
Symbol
problem

Symbol

Age
11 to 14
Challenge level
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Using the new operator $\oplus$, can you solve this equation?
Fifty Coins
problem

Fifty Coins

Age
11 to 14
Challenge level
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Cheryl finds a bag of coins. Can you work out how many more 5p coins than 2p coins are in the bag?
Crossover
problem

Crossover

Age
11 to 14
Challenge level
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The numbers 2 to 8 are to be placed in the diagram so that the row and column each adds to 21. Which numbers can replace x?
To Run or not to Run?
problem

To Run or not to Run?

Age
11 to 14
Challenge level
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If an athlete takes 10 minutes longer to walk, run and cycle three miles than he does to cycle all three miles, how long does it take him?
Named Products
problem

Named Products

Age
11 to 14
Challenge level
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Can you find the solution to this equation? Each of the different letters stands for a different number.
Magic 7
problem

Magic 7

Age
11 to 14
Challenge level
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Can you complete this magic square with the numbers from 7 to 15?
Adjacent Additions
problem

Adjacent Additions

Age
14 to 16
Challenge level
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In a 7-digit numerical code, each group of four consecutive digits adds to 16, and each group of five consecutive digits adds to 19. What is the sum of all 7 digits?
In the Hundreds
problem

In the Hundreds

Age
14 to 16
Challenge level
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For how many positive values of $n$ are both $\frac n2$ and $2n$ three-digit whole numbers?
I Love Musical Stars
problem

I Love Musical Stars

Age
14 to 16
Challenge level
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Each row and column has the total given. What is the value of the heart symbol?
Table Total
problem

Table Total

Age
14 to 16
Challenge level
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Can you find the sum of all of the numbers in the table?
Symmetric Reasoning
problem

Symmetric Reasoning

Age
14 to 16
Challenge level
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Can you sum up the solutions to this equation?
Pure Algebra
problem

Pure Algebra

Age
14 to 16
Challenge level
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Can you work out the product of $a$ and $b$ from the information in the question?
Bat and Ball
problem

Bat and Ball

Age
14 to 16
Challenge level
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Can you work out how much this bat costs?
Weighing the Baby
problem

Weighing the Baby

Age
14 to 16
Challenge level
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Weighing the baby at the clinic was a problem. Can you work out the total weight of the baby, the nurse and me from the information given?
Algebraic Differences
problem

Algebraic Differences

Age
14 to 16
Challenge level
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If $6x−y=21$ and $6y−x=14$, what is the value of $x−y$?
Well Read
problem

Well Read

Age
14 to 16
Challenge level
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If you know how many books each boy, girl and teddy bear borrowed from the library, can you work out the number of girls?
Oldest and Youngest
problem

Oldest and Youngest

Age
14 to 16
Challenge level
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Edith had 9 children at 15 month intervals. If the oldest is now six times as old as the youngest, how old is her youngest child?
Tennis Training
problem

Tennis Training

Age
14 to 16
Challenge level
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After tennis training, Andy, Roger and Maria collect up the balls. Can you work out how many Andy collects?
Placeholder: several colourful numbers
problem

Relative Angles

Age
14 to 16
Challenge level
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Can you work out the angles of a triangle from the relationships between them?
Square to a rectangle
problem

Square to a rectangle

Age
14 to 16
Challenge level
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Kevin has moved some tiles to change the shape of his patio from a square to a rectangle. What are the lengths of the sides of the rectangle?
Black and white socks
problem

Black and white socks

Age
14 to 16
Challenge level
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There are 20 black socks and some white socks in a drawer. Can you work out how many of the socks are white?
Placeholder: several colourful numbers
problem

Thousands of x

Age
14 to 16
Challenge level
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Can you solve this scary-looking equation?
Placeholder: several colourful numbers
problem

Traffic Tunnel

Age
14 to 16
Challenge level
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Will these vehicles fit through this tunnel?
Day of the Triffids
problem

Day of the Triffids

Age
14 to 16
Challenge level
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Jasmine buys three different types of plant. How many triffids did she buy?
Fractions of Fractions
problem

Fractions of Fractions

Age
14 to 16
Challenge level
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If you know that a fraction of X is the same as a different fraction of Y, can you work out X/Y?
Table Height
problem

Table Height

Age
14 to 16
Challenge level
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A table has blocks of wood placed on and next to it. Can you work out how tall it is?
Big Fish
problem

Big Fish

Age
14 to 16
Challenge level
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Granny has taken up deep-sea fishing! Last week, she caught a fish so big that she had to cut it into three pieces in order to weigh it...
Simultaneous Multiplying
problem

Simultaneous Multiplying

Age
14 to 16
Challenge level
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If $a \times b=2$, $b \times c=24$, $c \times a=3$ and $a$, $b$ and $c$ are positive, what is the value of $a+b+c$?
Monetary Difference
problem

Monetary Difference

Age
14 to 16
Challenge level
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Al, Bertie, Chris and Di have sums of money totalling £150... What is the difference between the amount Al and Di have?
Three Fruits
problem

Three Fruits

Age
14 to 16
Challenge level
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Quince, quonce and quance are three types of fruit. Can you work out the order of heaviness of the fruits?
Weighing Scales
problem

Weighing Scales

Age
14 to 16
Challenge level
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Can you work out how many spheres will balance a single pyramid?
Average Surroundings
problem

Average Surroundings

Age
14 to 16
Challenge level
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Can you work out Ali's age based on the diagram?
Sum = Product = Quotient
problem

Sum = Product = Quotient

Age
14 to 16
Challenge level
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Can you find a pair of numbers such that their sum, product and quotient are all equal? Are there any other pairs?
Reciprocal Values
problem

Reciprocal Values

Age
14 to 16
Challenge level
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Manipulate one algebraic fraction to solve another.
Near 10
problem

Near 10

Age
14 to 16
Challenge level
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10 must remain within easy reach...
Packing Boxes
problem

Packing Boxes

Age
14 to 16
Challenge level
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Look at the times that Harry, Christine and Betty take to pack boxes when working in pairs, to find how fast Christine can pack boxes by herself.
Alien Currency
problem

Alien Currency

Age
14 to 16
Challenge level
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The planet Zog has both green and blue bank notes. Can you work out how many zogs two green and three blue bank notes are worth?
Placeholder: several colourful numbers
problem

Nested square roots

Age
14 to 16
Challenge level
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Can you find the value of this expression, which contains infinitely nested square roots?
Placeholder: several colourful numbers
problem

A third of the area

Age
14 to 16
Challenge level
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The area of the small square is $\frac13$ of the area of the large square. What is $\frac xy$?