via BigBlueBoo

# Monthly Archives: October 2015

# Countdown

# #mathsTLP Summary 11th October 2015

**Lesson 1: Volume of Cones / Pyramids
**

@simonteaches oooh get them to build cubes out of square based pyramids #mathsTLP

—

solve my maths (@solvemymaths) October 11, 2015

@simonteaches Goes well with volume of a cone. Here's a nice hw on these two topics from @Stacy_Maths prethomework.weebly.com/uploads/4/0/4/… #mathsTLP

—

Jo Morgan (@mathsjem) October 11, 2015

@simonteaches AQA June 2014 paper 1 Higher has good nice question on pyramid/ frustum! #mathsTLP

—

Mark (@WinterOfDespair) October 11, 2015

@simonteaches nrich.maths.org/1408
geogebra.org/material/show/…
#mathsTLP

—

solve my maths (@solvemymaths) October 11, 2015

**Lesson 2: Simultaneous Equations (Elimination Method)**

@solvemymaths @fractionfanatic I'd started with a worded problem, with one co-eff matching, form equations, develop method from there

—

fmaths (@fmaths42) October 11, 2015

@fractionfanatic start with same coefficient of y, then of x, then one coefficient as factor of the other
#mathsTLP

—

solve my maths (@solvemymaths) October 11, 2015

@fractionfanatic @solvemymaths Its the way I'd always start for the algebraic method, guides students to where they need to get to #mathsTLP

—

fmaths (@fmaths42) October 11, 2015

@fractionfanatic @mathsjem #mathstlp Also bits of tes.com/teaching-resou…

—

Martin Armstrong (@TravellingBlue) October 11, 2015

**Lesson 3: Ratios**

@W4LDO
millions:
reflectionsinthewhy.wordpress.com/2014/05/26/sel…
map.mathshell.org/lessons.php?co…
teacher.desmos.com/tilepile
goo.gl/RYM7kR
#mathsTLP

—

Chris K (@k_sirhc) October 11, 2015

@k_sirhc @W4LDO and
solvemymaths.com/2015/04/28/5-m…
solvemymaths.com/2015/05/31/rat…
#mathsTLP

—

solve my maths (@solvemymaths) October 11, 2015

@W4LDO
goo.gl/7A3u3j
emergentmath.com/2013/05/02/if-…

—

Chris K (@k_sirhc) October 11, 2015

@W4LDO
goo.gl/Wy8WSq
goo.gl/aATPHp
180days2012-13.fawnnguyen.com/2013/06/03/day…
101qs.com/2038-bone-coll…

—

Chris K (@k_sirhc) October 11, 2015

@W4LDO There's a nice video clip on YouTube of a man blowing up different ratios of hydrogen and oxygen. #mathsTLP

—

Rob Anthony (@RobAnthony01) October 11, 2015

@W4LDO #mathstlp You could challenge students to say what facts they see in a simple image such as this ... http://t.co/Y43vhvF0js

—

Mary Pardoe (@PardoeMary) October 11, 2015

@W4LDO Got to go with the bar model! My prezi here has some useful examples prezi.com/mmqgbm9g1lek/s…

—

Mr Mattock (@MrMattock) October 11, 2015

@W4LDO As a plenary exercise I get my pupils to organise themselves into ratios of my choosing #mathsTLP

—

Gillian Mathewson (@gmathewson1) October 11, 2015

# Bounds Problem #1

# 007 Number Bonds

I’ve created a series of number bonds ‘workouts’ in the style of (the fantastic) Times Tables Rockstars.

There’s no website I’m afraid(!), these are just excel sheets that randomly generate numbers each time you load them. That means that you have an infinite variety. Hurrah!

There are:

3 Levels of difficulty for number bonds to 10 (add, subtract, mixed)

The same again (3 levels) for bonds to 20:

6 levels of difficulty for bonds to 100 (below is level 6):

and I’ve also added in 2 levels for bonds to 60 (time), 180 (angles) and 360 (more angles).

**MAKE SURE YOU READ THIS NEXT BIT:**

Each sheet has randomly generated numbers on it. That means that every time you do something (eg press enter), the whole sheet will change. That’s great for making different worksheets each week, but really bad if you want to reload an old one with exactly the same questions on it.

SO!! If you want to make a permanent copy of any single set of questions, then **print the page to pdf**.

Do that by selecting file / print but selecting PDF instead of a printer.

PS the answers are all in each sheet as well. Just change the font colour of the cells where the answers should go and voila, there are the answers.

Here is the excel file. All the different sheets are listed along the bottom of the file (as…excel sheets).

And if you’re into the whole playing music at the same time thing, here’s the james bond score and some classic film themes:

# Fun with Factorials

So recently I saw this on Twitter

I think I’ve actually seen two versions of the same idea in the last week or so. If you haven’t figured it out yet, the answer is 5!, not 5. As in, 5 factorial (5 x 4 x 3 x 2 x 1 = 120).

Hilarious (or not…). I found it kind of dumb, but it got me thinking that it might be fun to find a version of this that works both ways. ie the answer can be worked out to be 5, or 5!

For that to happen, the question needs to be done in one of two ways. In other words, some kind of order of operations problem, which means we need a multiplication or division in there somewhere. The challenge has been set!

So whilst I was sat in the car park waiting for my son’s sports stuff to finish, I opened the glove box, where my handy emergncy maths kit resides… a book and a pencil.

I decided to go with something along the lines of a + b x c , so that it could be (mis)calculated as (a + b)c rather than correctly as a + bc.

The key is that both answers would work – ie one gives me an answer of 5, and the other 5! (120).

Time for some awesome algebra. Click the image below to be able to read it.

by rearranging and fiddling around a bit, I’ve finally got expressions for b and c in terms of only a.

The only restriction on ‘a’ is that it cannot be 115, otherwise we’re dividing by zero to calculate ‘b’, and nobody wants that!

So now we need a number for ‘a’. I could put anything in, but for the question to look nice, the simpler the numbers the better.

You can see that ‘c’ is going to be a decimal unless ‘a’ is negative. I don’t want ‘a’ to be negative, otherwise the simplicity of the question will be gone. So I want to make sure that ‘c’, if it has to be a fraction, is a simple one. Well 1/2 is probably the simplest fraction there is, and to get that, I need ‘a’ to be equal to 230.

So now we have a = 230, and c = 0.5

Put the value of ‘a’ into our formula for ‘b’, and we get a nice round ‘-220’. The only way i can get that to be positive is if I sacrifice the simplicity of my fraction for ‘c’, but having a negative is no big deal for ‘b’ rather than ‘a’, because it’s not at the start of the question. It just means the question will be a subtraction and a multiplication rather than an addition and a multiplication. Fine by me. The final workings are below (again, click for enlargement)

Time to make it look pretty at the end:

# Squaring the Circle

via GeometricLoci