Skills Covered

How to Use This Pack

Five pages on rules that change one number into another. Page 1 has eight function machines: a number goes in, the rule is on the machine (like + 5 or × 3), and students write what comes out; the first machine is a worked example. Page 2 gives the rule on a machine and six tables with In and Out rows to finish. Page 3 has eight full tables and asks for the rule; a tip at the top shows why one pair is not enough, since In 2, Out 4 could be + 2 or × 2. Page 4 has six tables with a few full pairs to find the rule from, then missing ins and outs to fill in, including two division rules. Page 5 has six word problems about tricycle wheels, ages, ticket prices, muffins, sharing cookies and a growing plant: students finish each table, write its rule and finish a sentence about a number past the end of the table.

In the Classroom

Before page 1, play "function machine" with the class: you are the machine, students call out a number, and you say what comes out until someone can name your rule. Ask for a rule to be tested on every pair on page 3 before anyone writes it down. On page 4, talk about how to go backward: if the rule is × 5, divide by 5 to find what went in.

At Home

Take turns being the machine: one person picks a secret rule like "add 6" or "times 2," the other says a number in, and the machine says what comes out. After three or four tries, guess the rule, then test it on one more number.

Tips for Success

• Do the rule to the In number to get the Out number
• Test your rule on every pair in the table, not only the first one
• If the Out numbers are bigger, try adding or multiplying; if smaller, try subtracting or dividing
• To find a missing In, undo the rule: subtract instead of add, divide instead of multiply
• Read the labels in a word problem table to know what goes in and what comes out