# K-12 Math Puzzles from the Math Forum

Back to Math Problems, Puzzles, Tips & Tricks

1999 Puzzle - Judy Brown

Use the digits in the year 1999 and the operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial), along with grouping symbols, to write expressions for the counting numbers 1 through 100.

1998 Puzzle - Judy Brown

Use the digits in the year 1998 and the operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial), along with grouping symbols, to write expressions for the counting numbers 1 through 100.

1997 Puzzle - Ruth Carver

Challenge: Using the digits in 1997 and any operations, try to write equations that have the numbers from 0 to 100 as the answer.

Four 4's Puzzle - Ruth Carver

Challenge: Using four 4's and any operations, try to write equations that have the numbers from 0 to 100 as the answer.

1996 Puzzle - Ruth Carver

Challenge: Using the digits in 1996 and any operations, try to write equations that have the numbers from 0 to 100 as the answer.

## Math Line Puzzles

Can you connect the dots in a 3x3 grid using 4 straight lines?

Can you figure out how to plant 7 rosebushes so that they form 6 straight lines with 3 rosebushes in each line? Or 10 bushes in 5 lines with 4 in each? How about 19 in 9 lines with 5 in each?

Can you construct 9 triangles by drawing 3 straight lines through a capital M?

Can you move exactly two toothpicks to form four 1x1 squares?

## Critical Thinking Puzzles

A selection of brain teasers from Michael DiSpezio's new book, Critical Thinking Puzzles. Five puzzles, with solutions: Pyramid Passage, Spare My Brain, Putting It Together, Fractured Farmland, Kitchen Cups.