If you recall, Magic numbers are factors of ten. Professor Pig uses pancakes to teach us about adding past ten using magic number pairs.
This lesson which incorporates the beginning concept of the abacus by using the abacus flash cards, and a homemade simple abacus (below), was a great introduction to our next big theme in math which is how to use the abacus. I purchased three Japanese Abacuses and corresponding workbooks from Malaysia for next year, but with this wonderful introduction we have jumped ahead and begun the basics of calculating with an abacus now.
To make this abacus you need:
- One piece of elastic thread
- 20 beads, 10 each of 2 colors
- a permanent marker or paint
- A book larger enough for the beads and space to move them.
The 49 game is also a simple introduction towards to the abacus. It was a big hit with the boys. Here is how it is played.
Each player will need: 4 pennies, 1 nickle, and 4 dimes
The players will not really have to add numbers,just slide them around the board. Following the correct rules for placement of the coins will automatically give them the answer.
The object of this game is to get 49 cents, 1 nickle, 4 dimes, and 4 pennies add up to 49 cents. For this game use either the tetrahedron die or the cubic die you made in lesson 2. The cubic die will give you slightly faster game by allowing higher numbers.
Before laying, practice placing the coins on the board. You put down one penny at a time until 4 pennies are on the board. When you put the nickel down, you must at the same time sweep all the pennies off the boad. Then you can add four more pennies. Whne you get to 10 cents, you put down the dime then sweep the nickel and four pennies of the board. Tell them it is one move: "place and sweep" Make sure the players understand that every time they put down a nickel they must sweep off all the penies, and every time they put down a dime they must sweep off all the nickles and pennies. The game is incredibly straight forward. Just roll the dice and they earn that many cents for their board. The first player to get 49 cents wins!
There is one more lesson by Professor Pig called the 'The nine trick' which we will get to before the year is out. But for now the abacus has arrested our attention. Click click click and away we go...