Mathematicians at Work

Yesterday two students celebrated their 7th birthday!  Both students brought cupcakes to school to share with their friends.  This occurance turned into a mathematical investigation for our class. 

Brayden brought two trays of cupcakes for the class.  Each tray had 12 cupcakes.
Charles brought two trays of cupcakes for the class.  Each tray had 12 cupcakes.

The students worked in pairs ('math buddies') to find out:

• how many cupcakes there were altogether
• if everyone in our class ate one cupcake, how many cupcakes would be left over
• if everyone in our class ate two cupcakes, how many cupcakes would be left over

using equations

 open number line - 'jumps' backward to subtract

(attempts at using equations were unsuccessful)

 using equations

This dynamic duo decomposed the groups of 12 into 'friendly' groups

of 5s and 2s so it would be easier to count - way to go!

 drawing a picture and 'x'ing out to subtract

drawing a picture and counting

The students tried a variety of strategies to determine the number of cupcakes that we had received and how many would be left over after we served them.  The photos above were provided by students who volunteered to show their work during our Math Congress.