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Excel in math and science
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Arithmetic Puzzles
Arithmetic puzzles are Mad Libs for math: fill in the blanks with numbers or operations to make the equation true.
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
Used and loved by 4 million people
Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.
Concept Quizzes
Can we place a single digit in each \( \square \), such that the following equation is true:
\[ \square \, \times \, \square = 11 ? \]
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
Used and loved by 4 million people
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including olympiad champions, researchers, and professionals.
What (possibly different) single digit should we place in \( \square \) and \( \bigcirc\) to make the following equation true:
\[ 8 \square \div \bigcirc 8 = 3 \]
Give your answer as \( ( \square, \bigcirc ) \).
This is an arithmetic puzzle, where \( 8 \square \) would represent the 2-digit number 89 if \( \square = 9 \). It does not represent the algebraic expression \( 8 \times \square \). The same logic applies for the 2-digit integer \( \bigcirc 8\).
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
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examples, and problems from the community.
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Does there exist (possibly different) digits which we can replace the \( \square \) with, to make the following expression true:
\[ \square 2 \times 4 = \square 8 ? \]
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
Used and loved by 4 million people
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If in each of the squares, we must fill in a distinct digit, what is the minimum possible positive value of the difference?
\[ \begin{array} { l l l }
& \square & \square \\
- & \square & \square \\
\hline \end{array} \]
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
Used and loved by 4 million people
Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.
What identical digit can we place in \( \square \), to make the following statement true:
\[ \Large 1 \square \times \square = \square 9 ?\]