Can you use the digits on the left of this clock along with any mathematical operations to equal the digits on the right (also with any mathematical operations)?
Which times is this possible and which times impossible?
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Topics: Starter  Arithmetic  Mixed  Number  Problem Solving  Puzzles
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Previous Day  This starter is for 14 June  Next Day
Answers really depend on the level of mathematics involved so there are no definative answers to this activity.
Here are a selection of solutions covering the time from 9am to 9:30am
09 01  0x9=0  0x1=0 
09 02  0x9=0  0x2=0 
09 03  0x9=0  0x3=0 
09 04  0x9=0  0x4=0 
09 05  0x9=0  0x5=0 
09 06  0x9=0  0x6=0 
09 07  0x9=0  0x7=0 
09 08  0x9=0  0x8=0 
09 09  90  90 
09 10  0x9=0  1x0=0 
09 11  9^{0}=1  1^{1}=1 
09 12  9^{0}=1  1^{2}=1 
09 13  9^{0}=1  1^{3}=1 
09 14  9^{0}=1  1^{4}=1 
09 15  9^{0}=1  1^{5}=1 
09 16  9^{0}=1  1^{6}=1 
09 17  9^{0}=1  1^{7}=1 
09 18  9^{0}=1  1^{8}=1 
09 19  9^{0}=1  1^{9}=1 
09 20  0x9=0  0x2=0 
09 21  √9+0=3  2+1=3 
09 22  9^{0}=1  2÷2=1 
09 23  0+9=9  3^{2}=9 
09 24  √9+0=3, 3!=6  2+4=6 
09 25  √9+0=3  52=3 
09 26  √9+0=3  6÷2=3 
09 27  0+9=9  2+7=9 
09 28  9^{0}=1  8^{2}=64, 6+4=10, 1+0=1 
09 29  0+9=9  9^{2}=81, 8+1=9 
09 30  0x9=0  0x3=0 
For more ideas see Alan Sturgess' Maths Puzzle Investigation video.
Teacher, do your students have
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Here is the URL which will take them to a number game.
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The digital clock used on this page is adapted from code provided by Radoslav Dimov copyright © 2009.