Model that a number can be partitioned more than one way. Write 3 240 and show:
Then sort a handful of numbers into odd and even, pairing gumnuts: even numbers pair up with none left over; odd numbers always have one lonely gumnut.
Together 1. Partition 5 608 two different ways.
Together 2. Order these: 4 050, 4 500, 405, 4 005. Smallest first.
Together 3. Is 7 426 odd or even? How can we tell by the last digit?
Students complete the worksheet "Bundles & Pairs". Circulate and prompt: "What's another way to make that number?"