Material
- Perforated board with 100 holes (or grooves) in rows of 10 arranged in a square. At the left side of the board there is a little window with a slot for the insertion of the cards. Across the top of the board, the numbers 1 to 10 are printed (the multipliers).
- Set of cards from 1 to 10 (multiplicand).
- A disc. 100 beads.
- Prepared slips.
Direct Aim
Memorization of tables.
Age of Great Interest
5½ years plus.
Control of Error
The control chart. (See The Cumulative Law of Multiplication)
Presentation
- Take the table of 3.
- Slip the label of 3 into the slot at the side.
- Put the counter over the 1 at the top of the board.
- ‘How many times are we making 3? Once’
- Put in 3 beads, in a vertical row;
- move the counter to the 2.
- ‘How many times are we making 3? 2 times.
- Put 3 more beads in under the 2.
- ‘How many beads have we got? – 123, 456.
- So two times three are 6
- Continue in this way up to ten times three.
- Count vertically, from left to right.
Notes
- There is no writing done in the first presentation.
- Do not start with the table of 1.
- When the child starts to use the multiplication slips, encourage him to íill them in as he goes along.
- He should say the table over, when he has completed it:
2 twos are 4 and in writing 2×2=4
3 twos are 6 and in writing 3×2=6 etc.
- He starts with this table. Question him about the x sign.
Point of Interest
The counting of the beads and the square of each number.
Additional exercises
1. Prepared slips
a x 3 = 6 a =?
3 x b = 12 b=?
2. The children later make up their own equations putting any letter they choose in place of one number-and give them to a friend to do.
3. When the children have concrete experience of volume they can be shown volume of cube 2cm x 2cm x 2cm = 8 cubic cms and use their tables like this.