decimal system numeral cards:
…1-9 printed in green
…10, 20…90 printed in blue on double-sized cards
…100, 200…900 printed in red on triple-sized cards
…1000, 2000…9000 printed in green on quadruple-sized cards
Presentation: 1st Part
Individual Presentation. As the one and the ten cards are placed on the table, the child reads them. One hundred and one thousand are presented in a three period lesson. The cards are arranged as in the diagram. Then the child examines the particular characteristics of each numeral, its color and the number of zeros.
1. The cards are turned face down on the table. Without turning the card face up, the child identifies the numeral indicated by the teacher. How many zeros does it have? The card is turned up to control. Another time, the teacher asks the color of each numeral.
2. ‘Magician’. The teacher picks up the four cards arranging them in a pile weighted to the left. This arrangement is shown to the child. The cards are stood on end as the top cards slide into the second position. Where did all the zeros go? They seem to have disappeared, but they are still there. The cards are lifted one by one to reveal the zeros. The child performs the magic trick.
Presentation: 2nd Part:
The first four numeral cards, just previously presented, are lain in order. The remaining unit cards are placed in a column below one, the child being encouraged to read each as he lays it in position. This continues for the tens (one ten, two tens…), hundreds (one hundred, two hundred…), and thousands (one thousand, two thousand…). The three period lesson continues noting color and number of zeros as well. If the child is familiar with the names, twenty, thirty…, these may be supplemented. It is important for the child to realize that twenty (20) is two tens.
…to understand the orders of the decimal system.
…to turn the numerals for each of those four orders
Indirect Aim: to understand the importance of zeros in distinguishing the numerals.