This version includes 12 color (but printable in black and white) Guess My Rule cards with decimal addition rules.
The full version (Guess My Rule-Decimal Operations) includes 48 cards (12 rules per operation- addition, subtraction, multiplication, and division). See my store for details. Plenty of practice for developing decimal number sense! Use as a whole class game, small group activity, or in pairs.
To play, introduce one set of numbers at a time and let a partner try to figure out the rule. If rule is not guessed after first input/output pair, give the next pair of input/output numbers. Continue play until rule is guessed or all numbers have been revealed. Alternate option is to have the person with the card apply the rule to a new input if rule is not guessed after the four sets of numbers are used.