The Autumn Time Machine

Leaf chromatography on four leaves from one tree, from green to red: the yellow was inside the green leaf all summer. A step-by-step method with rubbing alcohol and coffee filters, what you should see, and why.

Leaf chromatography on four leaves from one tree, from green to red: the yellow was inside the green leaf all summer. A step-by-step method with rubbing alcohol and coffee filters, what you should see, and why.

Simmer autumn leaves in washing soda, brush away everything soft, and keep the network of veins that fed the leaf. Why it works, what the veins are for, and record pages for your results.

Collect acorns, predict, then test them in water: the ones that sink are alive. Look inside, keep the good ones cold for the winter and plant them in spring. Record pages and questions for every grade.

Write an expression for each short autumn story, substitute a value for the variable and work it out. Then decode a word from expressions, compare two hayride prices, and convert temperatures.

Picture codes with the order of operations and brackets. Crack each code to name an animal, then solve hibernation problems with a first taste of algebra.

Picture codes with multiplying and dividing. Crack each code to name an animal, then work through logic clues and number patterns about the animals' winter.

Picture codes with adding and taking away. Crack each code to name an animal, then find out which animals stay awake all winter and which ones sleep. Logic clues and word problems follow.

A 6×6 sudoku where some squares are hidden and only the products of the marked squares are given. Solve the grid, then use the fives to decode a hidden word.

A 6×6 sudoku where some squares are hidden and only the sums of the marked squares are given. Solve the grid, then use the fives to decode a hidden word.

Each shape stands for a number. Solve the chains of equations, put the shapes in order, and the letters spell hidden autumn words. The puzzles get harder, and the last one is yours to make.

A quick one-page puzzle. Cross out the pumpkins divisible by 2 and by 5, circle the ones divisible by 3, and read the hidden word. A bonus question at the end.

Find the path through the maze by stepping only on numbers divisible by 9. Colour the path, and the letters along it spell the answer. Some paths lead to dead ends!

Sort the numbers into baskets using the rules for 2, 5 and 10, and the letters spell three autumn words. Then fill in missing digits and follow a number trail. The rules are printed on the sheet.

Sort the numbers into baskets using the rules for 2, 3 and 6, and the letters spell three autumn words. Then fill in missing digits and follow a number trail. The rules are printed on the sheet.

Every picture hides a number. Find the numbers from the picture equations and read the hidden word. Starts with adding and taking away, then moves on to multiplying and dividing.

Long division and long multiplication practice with a twist: every answer turns into a letter, and the letters spell hidden autumn words.

Each shape stands for a number. Solve the equations to find the shapes, then follow the clues in Acorn the squirrel's story to work out where the acorns are hidden and how they last through the winter.