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Comments in green were written by me. Comments in blue were not written by me.
2019-12-17
@
Rob
: It looks to me like you've made mistakes in questions 1, 6, 8, and 9. The hints from the back of the pdf might help:
1.
How many numbers between 1 and 10,000 have 1 as their final digit? How many have 1 as their penultimate digit?
6.
How many ways can you write 1? 2? 3? 4? 5? What's the pattern?
8.
How many zeros does 10! end in? How many zeros does 20! end in? How many zeros does 30! end in?
9.
Carol’s sum is odd. What does this tell you about the 5- and 6-digit numbers?
Matthew
on
/blog/70
×1
×1
×2
×1
×2
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Logo Asteroids
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Mathsteroids on hyperbolic surfaces
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A surprising fact about quadrilaterals
Interesting tautologies
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Log-scaled axes
Feb 2020
PhD thesis, chapter ∞
PhD thesis, chapter 5
PhD thesis, chapter 4
PhD thesis, chapter 3
Inverting a matrix
PhD thesis, chapter 2
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PhD thesis, chapter 1
Gaussian elimination
Matrix multiplication
Christmas (2019) is over
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Visualising MENACE's learning
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A non-converging LaTeX document
TMiP 2019 treasure punt
Jul 2019
Big Internet Math-Off stickers 2019
Jun 2019
Proving a conjecture
Apr 2019
Harriss and other spirals
Mar 2019
realhats
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Christmas (2018) is over
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Christmas cross stitch
MENACE in fiction
Christmas card 2018
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Christmas (2018) is coming!
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Runge's Phenomenon
Jul 2018
World Cup stickers 2018, pt. 3
Mathsteroids
Jun 2018
World Cup stickers 2018, pt. 2
May 2018
A bad Puzzle for Today
Apr 2018
Building MENACEs for other games
Mar 2018
A 20,000-to-1 baby?
World Cup stickers 2018
Jan 2018
Origins of World War I
Christmas (2017) is over
2017
▼ show ▼
▲ hide ▲
Dec 2017
Christmas card 2017
Nov 2017
Christmas (2017) is coming!
MENACE at Manchester Science Festival
Jun 2017
Big Ben Strikes Again
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The end of coins of constant width
Dragon curves II
Feb 2017
The importance of estimation error
Jan 2017
Is MEDUSA the new BODMAS?
2016
▼ show ▼
▲ hide ▲
Dec 2016
Christmas (2016) is over
Video game surfaces
Christmas card 2016
Nov 2016
Christmas (2016) is coming!
Oct 2016
Logical contradictions
Palindromic dates
Sep 2016
Tube map kaleidocycles
Jul 2016
Solving the cross diagonal cover problem
Jun 2016
Braiding, pt. 2
Braiding, pt. 1
Making names in Life
May 2016
Euro 2016 stickers
Mar 2016
Proving Pythagoras' theorem
Dragon curves
The
Mathematical Games
of Martin Gardner
Jan 2016
Christmas (2015) is over
2015
▼ show ▼
▲ hide ▲
Nov 2015
Christmas (2015) is coming!
Oct 2015
How to kick a conversion
How much will I win on the new National Lottery?
Aug 2015
How OEISbot works
MENACE
Mar 2015
Optimal Pac-Man
Tube map stellated rhombicuboctahedron
Logic bot, pt. 2
Design your own flexagon
Jan 2015
Tube map Platonic solids, pt. 3
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▼ show ▼
▲ hide ▲
Nov 2014
Logic bot
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Electromagnetic Field talk
Jun 2014
Tennis maths
May 2014
World Cup stickers
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Countdown probability, pt. 2
Countdown probability
Mar 2014
New machine unfriendly £1 coin, pt. 2
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2013
▼ show ▼
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Dec 2013
Assorted christmaths
Pointless probability
Jul 2013
"Uncanny" royal coincidence
Raspberry Pi weather station
2012
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Nov 2012
Tube map Platonic solids, pt. 2
Oct 2012
Tube map Platonic solids
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news
cross stitch
finite group
logo
games
gerry anderson
sound
plastic ratio
go
manchester science festival
the aperiodical
data visualisation
numerical analysis
convergence
accuracy
martin gardner
matt parker
programming
puzzles
preconditioning
tennis
hats
royal institution
platonic solids
craft
palindromes
asteroids
christmas
tmip
map projections
interpolation
christmas card
finite element method
bempp
reuleaux polygons
stickers
dataset
hyperbolic surfaces
edinburgh
crochet
chess
sport
databet
errors
curvature
radio 4
newcastle
crossnumber
statistics
video games
football
gaussian elimination
computational complexity
ucl
nine men's morris
graphs
ternary
recursion
simultaneous equations
pi
datasaurus dozen
draughts
machine learning
pascal's triangle
weather station
golden ratio
runge's phenomenon
estimation
harriss spiral
golden spiral
final fantasy
propositional calculus
world cup
london underground
geogebra
data
binary
matrix of cofactors
graph theory
dinosaurs
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game show probability
rugby
oeis
flexagons
menace
pi approximation day
coins
raspberry pi
mathsjam
fractals
wool
weak imposition
polynomials
trigonometry
php
braiding
light
determinants
signorini conditions
python
stirling numbers
geometry
squares
people maths
latex
bodmas
cambridge
matrix of minors
captain scarlet
sobolev spaces
hexapawn
inline code
live stream
speed
rhombicuboctahedron
logs
countdown
fonts
dragon curves
error bars
standard deviation
reddit
boundary element methods
folding tube maps
phd
bubble bobble
noughts and crosses
misleading statistics
pizza cutting
turtles
advent calendar
zines
matrices
triangles
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manchester
quadrilaterals
big internet math-off
royal baby
fence posts
javascript
inverse matrices
folding paper
correlation
books
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arithmetic
dates
game of life
youtube
pac-man
guest posts
numbers
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anscombe's quartet
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mean
chebyshev
approximation
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© Matthew Scroggs 2012–2024
1. How many numbers between 1 and 10,000 have 1 as their final digit? How many have 1 as their penultimate digit?
6. How many ways can you write 1? 2? 3? 4? 5? What's the pattern?
8. How many zeros does 10! end in? How many zeros does 20! end in? How many zeros does 30! end in?
9. Carol’s sum is odd. What does this tell you about the 5- and 6-digit numbers?
on /blog/70