A quick (overdue) note on 2G Math.
It seems easy for adults — after all, we've been dealing with pennies, dimes, and dollars for a good many years now — but really "getting" our Base-10 math foundation is not easy for a young person.
One "one" is one, but one "ten" is ten.
How many tens in 20? Twenty? No, 20 tens is 200. Oh.
There are ten ones in ten, so how many tens in 100? How many ones in 100?
The educational "trick" with young minds is:
In the beginning (K3, PreK, K, 1G, 2G) Math begins with things, physical stuff that children can touch and manipulate.
That's where our 10-blocks come in:
Ones are little cubes
Tens are "sticks" (the size of 10 ones)
Hundreds are squares (you can line 10 ten sticks on top of a hundreds square)
Thousands are weighty cubes
We also use number lines, Rekenreks (you'll see these come out next week), and fingers!
As I tell every 2G class, I once had a 2G student who could count on his fingers faster than 90% of students could retrieve a memorized answer from long-term memory.
Finger-counting is GOOD!
Students should be encouraged to use their fingers until they don't need to anymore! Tools are good! It's what makes us human!
The other day we ran a marvelous exercise.
2G students entered the classroom, clipboard, pencil and answer sheet in hand.
They had to go to each of the ten stations -- not in any particular order -- note the question number, then jot down what number was represented by the 10-blocks.
We are happy to report: 2G did great!
Young students need a lot of reminding, practice, using, and seeing familiar concepts in new ways.
So don't forget, you have a Base-10 system in your pockets, wallets, purses: money!
Pennies are "ones"
Dimes are "tens"
Dollars are "hundred"
Have fun talking about, playing games with, challenging each other -- let your student challenge you! -- with Base-10 concepts.
If your child is scratching her/his head, let her/him manipulate the coins (or straws, or toothpicks). "Touch it" comes first!
Students also need a lot of practice with counting up, counting down, what comes before, what comes after... when counting by 1s, 2s, 5s and 10s.
Young students are just fine if they "stick" with one operation: Counting by 1s, what comes after 5, 17, 78, 106?
The problem comes when they must make the cognitive switches required to tackle the following:
Counting by 2s, what comes before 18?
Counting by 5s, what comes after 75?
Counting by 1s, what comes before 90?
Counting by 10s, what comes after 60?
Counting by 10s, what comes after 110?
Counting by 2s, what comes before 15?
While waiting in line -- say outside Art, or while waiting for a few folks to return from the loo -- we play the above "game."
It's a great one anytime you're waiting around, or stuck in traffic without anything to chat about! : )