Does this picture look right to you? An “optical illusion” is a shape or pattern that looks different from what was actually drawn. Straight lines that look curved, boxes that look flipped inside out…stuff like that. Well, here’s one that trips up your eyes along with your tongue! Starting in the top row of the picture, say the color of each word’s letters, instead of reading the word itself. How fast can you say all the right colors? It starts off all well and good, because the words and their colors match. But soon the words start showing up in colors that don’t match what they say. You keep wanting to read the words instead of saying the colors. See if you can trick your brain into behaving!
Wee ones: How many times does the word “red” show up in red letters like it should? Count them!
Little kids: Which row has the most words in it? Bonus: There are 5 purple-colored words, and 5 words that really are the word “purple” — and 1 of those words is in both groups (a purple “purple”). How many words is that in total?
Big kids: If you can get through each of the 8 rows in 3 seconds with no mistakes, how fast can you say the whole puzzle? Bonus: If you have 3 words — red, blue, and green — and those 3 colors, how many ways can you use all 3 colors to write those words without any word matching its own color?
Wee ones: 2 times (once in each of the first 2 rows).
Little kids: They’re all the same, at 4 words each! No row has more words than any others. Bonus: 9 words, since it would be 10 if the 2 groups didn’t share any words.
Big kids: In 24 seconds. Bonus: Only 2 ways: BGR, and GRB. The word red can be only blue or green. For each of those choices, 1 of the remaining colors will match 1 of the remaining 2 words, so instead of having 2 different orders for placing the last 2 colors, there’s only 1 way for each choice.
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.