Instructor Notes:

For materials preparations, click ‘Back to Main Menu’ button and select ‘Getting Started – EDC Setup’.

Read Every Day Counts Teacher’s Guide, Kanter and Gillespie, Great Source, 2005 or 2012 edition, p. 41.

As volunteers continue to update the Depositor every day of school, save discussions for days that offer the opportunity for students to try a variety of mental math strategies. On Day 27, for example, the addition is so simple it need not be discussed.

On the other hand, on Day 28, when the fourth hundred-dollar bill is earned, students can get the total in different ways. One student may suggest adding 378+28 “front end”, as 300 + 90 + 16 to get 406. Another student may suggest rounding 28 to 30 and adding that to 378 to reach 408 and then taking off 2 to get 406. Someone else may suggest taking 22 out of the 28 to put with the 378 to make 400 and then adding the 6 that were left to get 406. And of course there will be those who want to use the regrouping or “carrying” algorithm and put the ten from sixteen with the nine tens to make ten tens for a new hundred, resulting in 406.

Asking, “How will you add 28?” can certainly encourage lots of wonderful mental math leading to greater number sense.