Other tags that relate to Be Reasonable
Surds. Prime numbers. Making and proving conjectures. Rational and irrational numbers. Video. Mathematical reasoning & proof. Arithmetic sequences. Modular arithmetic. Interactivities. Proof by contradiction.There are 71 results
Broad Topics > Physical and Digital Manipulatives > Interactivities
Proof Sorter - Sum of an Arithmetic Sequence
Age 16 to 18 Challenge Level:
Put the steps of this proof in order to find the formula for the sum of an arithmetic sequence
Proof Sorter - the Square Root of 2 Is Irrational
Age 16 to 18 Challenge Level:
Try this interactivity to familiarise yourself with the proof that the square root of 2 is irrational. Sort the steps of the proof into the correct order.
Proof Sorter - Quadratic Equation
Age 14 to 18 Challenge Level:
This is an interactivity in which you have to sort the steps in the completion of the square into the correct order to prove the formula for the solutions of quadratic equations.
Polycircles
Age 14 to 16 Challenge Level:
Show that for any triangle it is always possible to construct 3 touching circles with centres at the vertices. Is it possible to construct touching circles centred at the vertices of any polygon?
Proof Sorter - Geometric Sequence
Age 16 to 18 Challenge Level:
Can you correctly order the steps in the proof of the formula for the sum of the first n terms in a geometric sequence?
Cyclic Triangles
Age 16 to 18 Challenge Level:
Make and prove a conjecture about the cyclic quadrilateral inscribed in a circle of radius r that has the maximum perimeter and the maximum area.
Factors and Multiples Game
Age 7 to 16 Challenge Level:
A game in which players take it in turns to choose a number. Can you block your opponent?
Solving with Euclid's Algorithm
Age 14 to 18 Challenge Level:
A java applet that takes you through the steps needed to solve a Diophantine equation of the form Px+Qy=1 using Euclid's algorithm.
Direct Logic
Age 16 to 18 Challenge Level:
Can you work through these direct proofs, using our interactive proof sorters?
Game of PIG - Sixes
Age 7 to 18 Challenge Level:
Can you beat Piggy in this simple dice game? Can you figure out Piggy's strategy, and is there a better one?
Attractive Tablecloths
Age 14 to 16 Challenge Level:
Charlie likes tablecloths that use as many colours as possible, but insists that his tablecloths have some symmetry. Can you work out how many colours he needs for different tablecloth designs?
Thank Your Lucky Stars
Age 14 to 16 Challenge Level:
A counter is placed in the bottom right hand corner of a grid. You toss a coin and move the star according to the following rules: ... What is the probability that you end up in the top left-hand. . . .
Jam
Age 14 to 16 Challenge Level:
To avoid losing think of another very well known game where the patterns of play are similar.
A Tilted Square
Age 14 to 16 Challenge Level:
The opposite vertices of a square have coordinates (a,b) and (c,d). What are the coordinates of the other vertices?
Excel Interactive Resource: Interactive Division
Age 11 to 16 Challenge Level:
Use an Excel to investigate division. Explore the relationships between the process elements using an interactive spreadsheet.
Matter of Scale
Age 14 to 16 Challenge Level:
Prove Pythagoras' Theorem using enlargements and scale factors.
Colour in the Square
Age 7 to 16 Challenge Level:
Can you put the 25 coloured tiles into the 5 x 5 square so that no column, no row and no diagonal line have tiles of the same colour in them?
Flower
Age 16 to 18 Challenge Level:
Six circles around a central circle make a flower. Watch the flower as you change the radii in this circle packing. Prove that with the given ratios of the radii the petals touch and fit perfectly.
Sliding Puzzle
Age 11 to 16 Challenge Level:
The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.
Nine Colours
Age 11 to 16 Challenge Level:
Can you use small coloured cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of each colour?
Guesswork
Age 14 to 16 Challenge Level:
Ask a friend to choose a number between 1 and 63. By identifying which of the six cards contains the number they are thinking of it is easy to tell them what the number is.
Changing Places
Age 14 to 16 Challenge Level:
Place a red counter in the top left corner of a 4x4 array, which is covered by 14 other smaller counters, leaving a gap in the bottom right hand corner (HOME). What is the smallest number of moves. . . .
Square It
Age 11 to 16 Challenge Level:
Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.
Spot the Card
Age 14 to 16 Challenge Level:
It is possible to identify a particular card out of a pack of 15 with the use of some mathematical reasoning. What is this reasoning and can it be applied to other numbers of cards?
Interactive Number Patterns
Age 14 to 16 Challenge Level:
How good are you at finding the formula for a number pattern ?
Power Match
Age 16 to 18 Challenge Level:
Can you locate these values on this interactive logarithmic scale?
Countdown Fractions
Age 11 to 16 Challenge Level:
Here is a chance to play a fractions version of the classic Countdown Game.
White Box
Age 7 to 18 Challenge Level:
This game challenges you to locate hidden triangles in The White Box by firing rays and observing where the rays exit the Box.
Interactive Workout - Mathmo
Age 16 to 18 Short Challenge Level:
Mathmo is a revision tool for post-16 mathematics. It's great installed as a smartphone app, but it works well in pads and desktops and notebooks too. Give yourself a mathematical workout!
Inside Out
Age 14 to 16 Challenge Level:
There are 27 small cubes in a 3 x 3 x 3 cube, 54 faces being visible at any one time. Is it possible to reorganise these cubes so that by dipping the large cube into a pot of paint three times you. . . .
Excel Interactive Resource: Fraction Multiplication
Age 11 to 16 Challenge Level:
Use Excel to explore multiplication of fractions.
Squaring the Rectangle
Age 14 to 18 Challenge Level:
Can you find a way to turn a rectangle into a square?
Napoleon's Theorem
Age 14 to 18 Challenge Level:
Triangle ABC has equilateral triangles drawn on its edges. Points P, Q and R are the centres of the equilateral triangles. What can you prove about the triangle PQR?
Cushion Ball
Age 16 to 18 Challenge Level:
The shortest path between any two points on a snooker table is the straight line between them but what if the ball must bounce off one wall, or 2 walls, or 3 walls?
Napoleon's Hat
Age 16 to 18 Challenge Level:
Three equilateral triangles ABC, AYX and XZB are drawn with the point X a moveable point on AB. The points P, Q and R are the centres of the three triangles. What can you say about triangle PQR?
Just Rolling Round
Age 14 to 16 Challenge Level:
P is a point on the circumference of a circle radius r which rolls, without slipping, inside a circle of radius 2r. What is the locus of P?
Trigonometric Protractor
Age 14 to 16 Challenge Level:
An environment that simulates a protractor carrying a right- angled triangle of unit hypotenuse.
Excel Interactive Resource: Haitch
Age 11 to 16 Challenge Level:
An Excel spreadsheet with an investigation.
Excel Interactive Resource: Fraction Addition & Fraction Subtraction
Age 11 to 16 Challenge Level:
Use Excel to practise adding and subtracting fractions.
Excel Interactive Resource: Multiples Chain
Age 11 to 16 Challenge Level:
Use an interactive Excel spreadsheet to investigate factors and multiples.
Excel Interactive Resource: Long Multiplication
Age 11 to 16 Challenge Level:
Use an Excel spreadsheet to explore long multiplication.
Magic W
Age 14 to 16 Challenge Level:
Find all the ways of placing the numbers 1 to 9 on a W shape, with 3 numbers on each leg, so that each set of 3 numbers has the same total.
Excel Interactive Resource: the up and Down Game
Age 11 to 16 Challenge Level:
Use an interactive Excel spreadsheet to explore number in this exciting game!
Excel Interactive Resource: Number Grid Functions
Age 11 to 16 Challenge Level:
Use Excel to investigate the effect of translations around a number grid.
Excel Interactive Resource: Equivalent Fraction Bars
Age 11 to 16 Challenge Level:
A simple file for the Interactive whiteboard or PC screen, demonstrating equivalent fractions.
Tilting Triangles
Age 14 to 16 Challenge Level:
A right-angled isosceles triangle is rotated about the centre point of a square. What can you say about the area of the part of the square covered by the triangle as it rotates?
Semi-regular Tessellations
Age 11 to 16 Challenge Level:
Semi-regular tessellations combine two or more different regular polygons to fill the plane. Can you find all the semi-regular tessellations?
Euclid's Algorithm I
Age 16 to 18
How can we solve equations like 13x + 29y = 42 or 2x +4y = 13 with the solutions x and y being integers? Read this article to find out.
NRICH is part of the family of activities in the Millennium Mathematics Project.