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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
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Christmas (2023) is coming!
Zines
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Chalkdust issue 17
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Logo Asteroids
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Mathsteroids on hyperbolic surfaces
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The databet
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Off-by-one errors
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Build your own MENACE
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Happy ((4τ)-(π+g))-11 Approximation Day!
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A surprising fact about quadrilaterals
Interesting tautologies
Mar 2020
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
Jan 2020
PhD thesis, chapter 1
Gaussian elimination
Matrix multiplication
Christmas (2019) is over
2019
▼ show ▼
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Dec 2019
Visualising MENACE's learning
Christmas card 2019
Nov 2019
Christmas (2019) is coming!
Sep 2019
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
Jan 2019
Christmas (2018) is over
2018
▼ show ▼
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Dec 2018
Christmas cross stitch
MENACE in fiction
Christmas card 2018
Nov 2018
Christmas (2018) is coming!
Sep 2018
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
Mar 2017
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
2014
▼ show ▼
▲ hide ▲
Nov 2014
Logic bot
Sep 2014
Electromagnetic Field talk
Jun 2014
Tennis maths
May 2014
World Cup stickers
Apr 2014
Countdown probability, pt. 2
Countdown probability
Mar 2014
New machine unfriendly £1 coin, pt. 2
New machine unfriendly £1 coin
2013
▼ show ▼
▲ hide ▲
Dec 2013
Assorted christmaths
Pointless probability
Jul 2013
"Uncanny" royal coincidence
Raspberry Pi weather station
2012
▼ show ▼
▲ hide ▲
Nov 2012
Tube map Platonic solids, pt. 2
Oct 2012
Tube map Platonic solids
Tags
a gamut of games
squares
binary
cambridge
data visualisation
the aperiodical
folding paper
national lottery
braiding
countdown
game show probability
folding tube maps
pythagoras
live stream
matrices
harriss spiral
reuleaux polygons
zines
london underground
logs
golden ratio
quadrilaterals
dataset
gerry anderson
correlation
graphs
chebyshev
realhats
hannah fry
hats
edinburgh
bempp
nine men's morris
php
european cup
boundary element methods
bodmas
determinants
world cup
mean
manchester science festival
video games
sound
speed
rugby
wool
draughts
youtube
royal baby
go
gaussian elimination
programming
dates
gather town
palindromes
graph theory
radio 4
propositional calculus
accuracy
pizza cutting
mathslogicbot
computational complexity
inverse matrices
phd
newcastle
pascal's triangle
plastic ratio
crochet
latex
books
games
javascript
recursion
weather station
hyperbolic surfaces
christmas card
stirling numbers
fractals
databet
flexagons
chalkdust magazine
tennis
puzzles
finite element method
map projections
24 hour maths
pi
signorini conditions
runge's phenomenon
people maths
geometry
anscombe's quartet
pi approximation day
noughts and crosses
final fantasy
fence posts
raspberry pi
bubble bobble
oeis
weak imposition
standard deviation
talking maths in public
christmas
arithmetic
convergence
electromagnetic field
big internet math-off
london
matrix of cofactors
rhombicuboctahedron
crossnumber
frobel
trigonometry
finite group
martin gardner
news
mathsteroids
stickers
menace
matrix of minors
datasaurus dozen
simultaneous equations
captain scarlet
dinosaurs
data
misleading statistics
coins
golden spiral
inline code
guest posts
preconditioning
estimation
exponential growth
polynomials
matrix multiplication
craft
fonts
ucl
sobolev spaces
cross stitch
logic
tmip
wave scattering
triangles
turtles
numbers
python
hexapawn
approximation
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advent calendar
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interpolation
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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