Which One Doesn’t Belong?

upper left: 9.<br />
upper right: 16.<br />
lower left: 25.<br />
lower right: 43.

numbers 1

by Pam Wilson

upper left: 3. upper right: 27. lower left: 123. lower right: 31

numbers 2

by Mary Bourassa

upper left: 17. upper right: 26. lower left: 44. lower right: 65.

numbers 3

by Mary Bourassa

upper left: 121. upper right: 16. lower left: 9. lower right: 73.

numbers 4

by Isabelle & Noah Bourassa

upper left: 36. upper right: 99. lower left: 9. lower right: 123.

numbers 5

by Isabelle Bourassa

upper left: one-half. upper right: five-thirds. lower left: two-tenths. lower right: two-fifths.

numbers 6

by Erick Lee

upper left: one-twentieth. upper right: twenty twenty-fifths. lower left: two thirds. lower right: five fourths

numbers 7

by Hélène Matte

upper left: 1:7. upper right: 2:14. lower left: 3:11. lower right: 7:49.

numbers 8

by Mrs. Morgan

Four clocks. upper left: analog, reading 9:32. upper right: digital reading 9:31 PM. lower left: digital reading 8:31. lower right: digital reading 9:32. There is a red light illuminated in the upper right of this last clock.

numbers 9

by Andrew Gael

All are addition problems, vertically set up and solved. upper left: 5231 + 4331 = 9562. upper right: 3696 + 6939.= 10,635. lower left: 1842 + 1614 = 3456. lower right: 2184 + 4812 = 6996

numbers 10

by Bridget Dunbar

upper left: 20 squared + 21 squared = 29 squared. upper right: 3 squared + 4 squared = 5 squared. lower left: a squared + b squared = c squared. lower right: (negative 1) squared + 0 squared = 1 squared.

numbers 11

by Andrew Gael

All images are vertically oriented dominos.upper left: Two fours. upper right: Six on top; five on bottom. lower left: Three on top; zero on bottom. lower right: Two on top; three on bottom.

numbers 12

by Joe Schwartz

upper left: 12 + 13 = 25. upper right: 2 + 3 = 5. lower left: 14 + 14 = 28. lower right: 0 + 1 = 1.

numbers 13

by Simon Gregg

upper left: 0.5. upper right: 0.25. lower left: 0.75. lower right: 0.3, with a vinculum over the 3.

numbers 14

by Pierre Tranchemontagne

upper left: negative one fourth. upper right: 40%. lower left: three halves. lower right: one sixth.

numbers 15

by Mishaal Surti

All are dice with one face showing. upper left: The number “5”. upper right: One dot. lower left: Small die with five dots. lower right: This is the only die that is a different color. It is blue with five white dots.

numbers 16

by Andrew Gael

upper left: 54. upper right: 64. lower left: 81. lower right: 144.

numbers 17

by Nick Johnson

upper left: 75. upper right: 65. lower left: 117. lower right: 52.

numbers 18

by Johnothon Sauer

upper left: 32. upper right: 64. lower left: 81. lower right: 144.

numbers 19

by Natasha Crawford & Kathy Gruzynski

All objects are birthday-candle digits laid on a piece of paper, which sits on a plaid tablecloth. upper left: 1. upper right: 9. lower left: 36. lower right: 45.

numbers 20

by Raül Fernández

upper left: 4 x 10.56 = 42.24. upper right: 5 x 0.432 = 2.18. lower left: 5.6 x 1.2 = 6.72. lower right: 0.03 x 2 = 0.06

numbers 21

by Colleen Phillips

upper left: 33%. upper right: one third. lower left: five thirds. lower right: .6, with a vinculum over the 6

numbers 22

by Erick Lee

upper left: 1. upper right: 64. lower left: 729. lower right: 216

numbers 23

by Amy Ruzicka

All objects are numbers in the style of digital clocks. upper left: a “2” in green. upper right: a slightly italicized “1” in blue. lower left: a “3” in white. lower right: a “5” in red; the lights are dappled as though made of smaller pixels.

numbers 24

by Ilona Vashchyshyn

upper left: 56. upper right: 45. lower left: 32. lower right: 24.

numbers 25

by Beth Benjamin

upper left: 2 x 8, with two circled groups of eight stars each. upper right: 8 + 8, with two groups of stars. Each group is two rows of four stars. lower left: 4x4, with four rows of four stars. lower right: 8 x 2 with two columns of eight dots.

numbers 26

by Elizabeth Brandenburg

All objects are sideways dominos. upper left: Two on the left; six on the right—grouped as a group of five, plus one. upper right: Four on the left and also on the right. lower left: Three on the left; five on the right. lower right: Four on the left; five on the right.

numbers 27

by Heather Heon

upper left: 8 + 6. upper right: 7 + 7. lower left: 8 + 7. lower right: 5 + 9

numbers 28

by Beth Benjamin & René Ammann

upper left: 5 + 5. upper right: 2 + 8. lower left: 9 + 1. lower right: 3 + 9

numbers 29

by Caroline Scott

upper left: (-2) to the fourth power. upper right: -2 to the fourth power (no parentheses). lower left: 2 to the negative-fourth power. lower right: 4 to the one-half power.

numbers 30

by Chris Bolognese

upper left: (19π) over 6. upper right: 1110°. lower left: negative (11π) over 6. lower right: (7π) over 3.

numbers 31

by Chris Bolognese

upper left: 2 + 4 + 8. upper right: 7 + 6 + 7. lower left: 6 + 11 + 5. lower right: 2 + 9 + 4 + 3.

numbers 32

by Heather Heon

upper left: 3.14. upper right: 22/7. lower left: π. lower right: 3.14, with a vinculum over the 1 and the 4.

numbers 33

by Jennifer Wilson

All objects are sequences of four numbers, stacked on top of each other, and right-aligned. upper left: 7; 70; 700; 7000. upper right: 2; 200; 20,000; 2,000,000. lower left: 8; 80; 800; 80,000. lower right: 0.5; 5.0; 50.0; 500.0.

numbers 34

by Caroline Scott

upper left: 3 - 4i. upper right: square root of negative 81. lower left: -2 + i. lower right: -15.

numbers 35

by Chris Duran

All objects are sequences of numbers, separated by commas. upper left: 5, 9, 13, 17, 21, … upper right: 5, 15, 45, 135, 405, … lower left: 5, 2, -1, -4, -7, … lower right: 10, 13, 16, 19, 22, …

numbers 36

by Jennifer Thien

All objects are sequences of numbers, separated by commas. upper left: 1, 1, 2, 3, 5, 8, … upper right: 2, 4, 8, 16, … lower left: -1, 1, 3, 5, 7, … lower right: 100, 99, 98, 97, …

numbers 37

by Stephanie Orosz

All objects are sequences of fractions, separated by commas. upper left: 1/4, 8/16, 48/64. upper right: 3/9, 2/9, 1/9. lower left: 1/5, 2.5/5, 4/5. lower right: 1/16, 8/16, 64/16.

numbers 38

by Sean Corey