A selection of puzzles, many from the Junior or Intermediate Maths Challenges. Includes animated solutions. Good for promoting discussion and stimulating interest as starters, plenaries or extension. Powerpoint has clickable contents page to choose and move between puzzles.

A powerpoint including examples, worksheets and solutions on 3D sketching of prisms and other solids, nets of 3D solids, drawing on isometric paper and plans/elevations. Worksheets at bottom of presentation for printing.

The last of five complete lessons on linear sequences. Looks at patterns of squares or lines that each form a linear sequence. Adapted from a resource by another TES user called flibit (who has made some excellent resources). Printable worksheets included.

A complete lesson on the scenario of using the sine rule to find an obtuse angle in a triangle. Given the connection this has with triangle congruence and the graph of sine, these ideas are also explored in the lesson. Designed to come after pupils have spent time doing basic sine rule questions and have also encountered the graph of sine beyond 90 degrees. Activities included: Starter: A goal-free question to get pupils thinking, that should help recap the sine rule and set the scene for the rest of the lesson. Main: A prompt for pupils to construct a triangle given SSA, then a closer look at both possible answers. Depending on the class, this could be a good chance to talk about SSA being an insufficient condition for congruence. A related question on finding an unknown angle using the sine rule. Pupils know there are two answers (having seen the construction), but can they work out both answers? This leads into a closer look at the symmetry property of the sine graph, and some quick questions on this theme for pupils to try. Then back to the previous question, to find the second answer. This is followed by four similar questions for pupils to practice (finding an obtuse angle using the sine rule) Two extension questions. Plenary: A slide to summarise the lesson as simply as possible. Answers and printable worksheets included. Please review if you buy as any feedback is appreciated!

A set of challenging activities using Pythagoras’ theorem. Activities included: Starter: Given two isosceles triangles, pupils work out which one has the larger area. Main: Examples/practice questions, followed by two sets of questions on the theme of comparing area and perimeter of triangles. Both sets start with relatively straight forward use of Pythagoras’ theorem, but end with an area=perimeter question, where pupils ideally use algebra to arrive at an exact, surd answer. Plenary: Not really a plenary, but a very beautiful puzzle (my take on the spiral of Theodorus) with an elegant answer.

A complete lesson on solving two step equations using inverse operations. Does include some decimals, as I wanted to give a more complete example set and make it hard for pupils to just use trial and error to find solutions. As such, I would let pupils use calculators. Activities included: Starter: A set of questions to check that pupils can evaluate two step expressions like 2x+3, given a value of x Main: A prompt to discuss the differences between two equations (a one step and a two step with the same solution), to get pupils thinking about how they could approach the latter. Examples and a set of questions on using inverse operations to reverse a two step flowchart and solve its corresponding equation. These have been deigned to further reinforce the importance of BIDMAS when interpreting an algebraic expression, so the emphasis is on quality not quantity of questions. A more challenging task of pupils trying to make an equation with a certain solution. Designed to be extendable to pupils looking for generalistions. Plenary: A prompt to discuss a few less obvious one-step equations (eg x+8+3=20) Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson on bearings problems with an element of trigonometry or Pythagoras’ theorem. Activities included: Starter: Two sets of questions, one to remind pupils of basic bearings, the other a matching activity to remind pupils of basic trigonometry and Pythagoras’ thoerem. Main: Three worked examples to show the kind of things required. A set of eight problems for pupils to work through. Plenary: A prompt for pupils to reflect on the skills used during the lesson. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson (or maybe two) for introducing the circumference rule. Activities included: Starter: Prompts for pupils to discuss and share definitions for names of circle parts. Main: Link to an online geogebra file (no software required) that demonstrates the circumference rule. Quickfire questions to use with mini whiteboards. A worksheet of standard questions with a progression in difficulty. A set of four challenging problems in context, possibly to work on in pairs. Plenary: Pupils could discuss answers with another pair, or there could be a whole-class discussion of solutions (provided) Printable worksheets and answers included. Please review it if you buy as any feedback is appreciated!

A complete lesson for first introducing how to find angles in a right-angled triangle using a trig ratio, but as a pupil-led investigation. Intended to come after pupils have practiced identifying hypotenuse/opposite/adjacent and calculating sin/cos/tan. Activities included: Starter: A set of questions to check pupils can correctly calculate sin, cos and tan from a triangle’s dimensions. Main: A structured investigation where pupils: Investigate sin, cos and tan for triangles of different size but the same angles (i.e. similar triangles), by measuring dimensions of triangles and calculating ratios Investigate what happens as the angle varies by measuring dimensions of triangles, calculating ratios, and plotting separate graphs of sin, cos and tan. Using their graphs to estimate angles for conventional SOHCAHTOA questions (i.e. finding an angle given two sides) Plenary: A prompt to get pupils to discuss/reflect on their understanding of the use of trig ratios. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson on finding an angle in a right-angled triangle using trig ratios. Designed to come after pupils have been introduced to the ratios sin, cos and tan, and have investigated how the ratios vary. Please see my other resources for complete lessons on these topics. Activities included: Starter: Provided with the graph of y=sinx, pupils estimate sinx for different values of x and vice-versa. Main: Slides to introduce use of scientific calculators to find accurate values for angles or ratios. Examples of the basic method of finding an angle given two sides. Includes graphs to reinforce what is happening. Quick questions for pupils to try and provided feedback. A worksheet of questions with a progression in difficulty. Starts with standard questions, then moves on to more challenging ones (eg finding the smallest angle in a non-right-angled, isosceles triangle). Plenary: A final question to check pupils’ understanding, but also with a combinations/logic element. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson on the theme of using Pythagoras’ theorem to look at the distance between 2 points. A good way of combining revision of Pythagoras, surds and coordinates. Could also be used for a C1 class about to do coordinate geometry. Activities included: Starter: Pupils estimate square roots and then see how close they were. Can get weirdly competitive. Main: Examples and worksheets with a progression of difficulty on the theme of distance between 2 points. For the first worksheet, pupils must find the exact distance between 2 points marked on a grid. For the second worksheet, pupils find the exact distance between 2 coordinates (without a grid). For the third worksheet, pupils find a missing coordinate, given the exact distance. There is also an extension worksheet, where pupils mark the possible position for a second point on a grid, given one point and the exact distance between the two points. I always print these worksheets 2 per page, double sided, so without the extension this can be condensed to one page! It may not sound thrilling, but this lesson has always worked really well, with the gentle progression in difficulty being enough to keep pupils challenged, without too much need for teacher input. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson for first teaching pupils how to express a number as a product of its prime factors using a factor tree. Activities included: Starter: Three puzzles relating to prime numbers, intended to increase pupils’ familiarity with them. Main: Examples and questions (with a progression of difficulty and some intrigue). Plenary A ‘spot the mistake’ question. No worksheets required and answers included throughout. Please review it if you buy as any feedback is appreciated!

A complete lesson on gradient of curves. Examples and questions on calculating average gradient between 2 points on a curve and estimating instantaneous gradient at a point. Printable worksheets and answers included. Please review it if you buy as any feedback is appreciated!

A complete lesson looking at the associative and commutative properties of multiplication. Activities included: Starter: A simple grid of times table questions, includes ‘reversals’ (eg 7 times 9 and 9 times 7) to get pupils thinking about the commutative property. Main: Visual examples to get pupils thinking about commutativity of multiplication and non-commutativity of division. Pupils could explore further using arrays or Cuisenaire rods. Visual examples to get pupils thinking about associativity of multiplication and non-associativity of division. Pupils could explore further using pictorial representations. Three short activities where pupils make use of the commutative and associative properties of multiplication to make calculations. The last provides opportunities for pupils to create their own puzzles. Plenary: A maths ‘trick’ that uses the same properties. Please review if you buy as any feedback is appreciated!

A complete lesson on finding percentages of an amount using non-calculator methods, by relating them to the key percentages of 10%, 25% and 1%. See the cover image to get an idea of the intention of the lesson. Activities included: Starter: A set of questions to recap on finding 50%, 25%, 75%, 10%, 5%, 20% and 1% of an amount. Main: Some slides to introduce the idea of using the key percentages to find other percentages. A worksheet to consolidate these ideas, followed by three flowcharts in the style of the cover image, where pupils are given a starting number and work out all the percentages. The starting numbers get progressively more difficult. I use this as a non-calculator task, but it could be used with calculators too. An extension task where pupils work out some percentages not included in the flowcharts, by combining percentages. Plenary: A great discussion question, looking at four possible ways to calculate 75% of a number. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson on using knowledge of gradient to find the equation of a line perpendicular to a given line. Nothing fancy, but provides clear examples, printable worksheets and answers for this tricky topic. Please review it if you buy as any feedback is appreciated!

A complete lesson on using knowledge of gradient and y-intercept to plot a line, given its equation. Progresses from positive integer gradients to fractional and/or negative gradients. Examples, printable worksheets and answers included. Please review it if you buy as any feedback is appreciated!

A complete lesson for first teaching how to simplify a fraction. Activities included: Starter: Some quick questions to test if pupils can find the highest common factor of two numbers. Main: A short activity where pupils sort a selection of fractions into two groups, based on whether they are simplified or not. Example question pairs to quickly assess if pupils understand how to simplify. A set of straightforward questions with a progression in difficulty. A challenging extension where pupils must arrange four digits to create fractions that simplify to given fractions. Plenary: Some questions in context to reinforce the key skill and also give some purpose to the process of simplifying fractions. Optional worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson on increasing or decreasing by a percentage. Activities included: Starter: A template for pupils to work out lots of different percentages of £30 Main: Examples and a set of straight-forward questions making percentage changes. A connect 4 game for pupils to play in pairs, taking it in turns to work out percentage changes and win squares on a grid. A few questions to discuss about the game. A puzzle where pupils arrange numbers and percentage change statements to make a loop. Plenary: Some examples looking at making a percentage decrease a different way - eg decreasing by 25% by directly working out 75% Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!

A complete lesson on the equation of a circle with centre the origin. The intention is to get pupils familiar with not only the format of the equation of a circle, and a derivation of the equation, but also problems involving coordinates on a circle. Activities included: Starter: A related question where pupils try to identify which of three given points are closer to the origin, before considering what must be true if points are a given distance from the origin. Main: The starter leads directly into a clear definition of the equation of a circle, followed by a set of quick diagnostic whole-class questions to check for understanding. Example-question pairs of increasingly difficult problems involving coordinates on circles, followed by a set of three worksheets. The last one is more of a mini-investigation, with opportunities for pupils to conjecture and generalise. Plenary: Three final puzzles to check for understanding. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!