Explore: Penny Collection (25 min)

You may use counters or pennies to solve this problem. You may also work with a partner.

There is a collection of pennies.

• When the pennies are put in groups of 2 there is one penny left over.
• When the pennies are put in groups of 3 there is one penny left over. 
• When the pennies are put in groups of 5 there is one penny left over.
• When the pennies are put in groups of 6 there is one penny left over. 
• But when they are put in groups of 7 there are no pennies left over.

How many pennies could there be?

 Use actual pennies, rocks, beans, or any collection of objects to solve this mystery.  

Student materials for printing (optional): click to view

Student materials online (no printing): click to view

 or use the applets below...

 You might consider using this Hundreds Chart to track your thinking.