Twenty three "defuse the bomb" worksheets and answers on various topics including vectors, inequalities (solving, number lines and regions), shapes, bearings, rearranging formulae, transforming functions, trigonometry in right-angled triangles, similarity and surface area. These are self-marking to the extent that if their answer doesn't appear in the list of possible answers then they need to check what they've done which allows students to just get on and grow in confidence.

Mick Carter, landlord of the Queen Vic in Eastenders, requires help with some fractions that he’s trying to shift. Can your class help him? This involves converting between mixed and improper fractions as well as calculating with them. Eastenders theme tune is optional…

Just one “Crack The Safe” activity on differentiation, involving differentiating, finding gradients and turning points. There are six questions with three possible answers for each. The wrond answers may generate discussion as to what has been done, but ultimately this is a self-checking worksheet that allows the teacher to help those who need it whilst others get on. I use these for starters or plenaries but use them how you wish.

Just the one Crack The Safe activity on functions, including substitution, inverses and composite functions. There are six question each with three possbile answers so students can self-check whilst the teacher help those who require it. The incorrect answers might create discussion as to how they came about too. I use these as starters and plenaries but use them how you like.

Twenty seven different algebra “Crack The Safe” activities. These have questions with a choice of potential answers (more than the number of questions to avoid answers by elimination). These are designed to allow students who are confident to get on and self-check answers (if their answer doesn’t appear they have made a mistake)whilst the teacher can help those who require it. These can be used as starters, plenaries or main task and can generate discussions. They are all available individually.

Twenty seven “Crack The Safe” activities (18 geometry and 9 data) where students have the ability to self-check their answers whilst the teacher helps those who require it. These can be used as starters, plenaries or main tasks and can generate discussion regarding the incorrect answers. Each of these is available individually.

Twenty seven separate worksheets (and answers) using the “Crack The Safe” template. These have questions and potential answers (more answers than questions to negate guessing or process of elimination answers). These allow teachers to help those who need it whilst others can self-check (if their solution appears in the set of potential solutions then they are good to go). You can use these as starters, plenaries or main tasks. These are all available individually.

This set of two worksheets is designed to force students to show their workings and not use a calculator when simplifying surds. There are straightforward simplifying, expanding brackets and rationalising the denominator with space to write working etc.

Two codebreakers (the first one is slightly easier than the second) where students must identify the equation of a trigonometric function from the graph, resulting in the punchline to a cheesy joke. The scale is as large as I can make it I’m afraid so I apologise that it is small. I used Desmos to draw the functions.

The usual stuff; cheesy joke revealed upon answering some questions.

Ten questions, each answered by four people. One of them has got the answer correct, the other three have got it wrong. Students find who got the answer correct then try to figure out what the others did wrong. This should lead to some nice discussion as either a starter or plenary, but you can clearly use it however you like.

We put on a Stem Day for Year 6 students and decided to do binary as the topic for a 45 minute session. This takes students through converting between binary and decimal numbers, including a couple of codebreakers (we produced a Stem leaflet for them to take away). The PowerPoint moves on to adding and subtracting in binary if you need it. It went well and was delivered by a range of people so if it’s useful to you… There’s even a bonus codebreaker on adding and subtracting in binary.

Twenty-five of the usual stuff (answer the questions, get a terrible joke), written between the dates in the title and covering topics that needed more codebreakers (in my opinion) or pushing a little further. There are plenty of statistical graph ones (box plots, pie charts, bar charts) plus simplifying expressions, surds (partially simplified to avoid calculator use), compound measures, including distance and speed-time graphs amongst other things. Each one comes with answers. Each of these has been uploaded for free as they have been written, so they are yours for free if you want them.

The usual: answer the questions on the cumulative frequency graphs, discover the punchline.

Read the box plots carefully and discover the punchline to a cheesy gag… Errors corrected…

One on a basic histogram and another using frequency polygons; the usual terrible jokes are revealed.

One tree diagram, numerous questions to figure out a cheesy joke. This involves counters and replacement.

There are twelve transformations here, all of which have more than one solution; this asks students to find as many solutions that work, including reflections, translations, rotations and enlargements with negative scale factors. I did this with a class and offered rewards for any solutions I hadn’t listed which seemed to motivate them even more! Solutions are on a separate slide to enable printing.

Four slides of four questions where you are given the answer but the question is missing some important information. Students must work out what information would work there; some have just one answer, some have many answers. This is designed for students to demonstrate their understanding and to create discussion.

A really lame joke this time, but that will surprise few. How many unique outcomes are there in each situation?