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Basic Mathematics Warmups

These problems and puzzles will put your deductive reasoning ability to the test and reinforce your mathematical skills. See more

Mental Shortcuts - Intermediate

         

Using the properties of decimals and the distributive rule, can you quickly find \( 15\% \) of 64?

Hint: \( 15 \% = 10\% + 5\% \).

Using the distributive rule, which of these are equivalent to \( 7 \times 64 + 7 \times 6? \)

Using the perfect square identity, which of these is equivalent to \( 81^2 ? \)

Hint: \( (a+b)^2 = (a+b) \times ( a +b) \).

Using the difference of two squares identity, which of these is equivalent to \( 5.7 \times 6.3 ? \)

Hint: \( a^2 - b^2 = (a+b)(a-b) \).

\[35 \times 28 = \, ? \]

(No calculators! Use your head and the hint above.)

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