In fourth grade, the first standard I like to tackle is CCSS 4.NBT.A.2, which gets kids reading and writing large numbers. Here's how our lesson went this week. First, we talked about the Base-10 number system. My students had no idea what I was talking about! They tried to tell me that we have a Base-10 system because there are only ten symbols, 0 through 9. I explained that man made up the ten symbols, and that ancient civilizations had used different bases. That was a hard thing for them...
