An operation is an action done on numbers, such as, counting. Numbers are not only used for counting as one, two, three, etc., but also to indicate sequence as first, second, third, etc.
As numbers are counted they stand for increasing quantity. This may be represented pictorially on a number line, where numbers are placed at equal distances on a line. These numbers increase sequentially from left to right. One may then use this representation to compare numbers, or to demonstrate how numbers may be combined to obtain new numbers.
Numbers may be visualized as sets, or collections of objects. A pile of pennies may be used as a set for demonstrating basic operations with numbers.
The combining of two numbers together is called addition. This may be done by counting a number to the right from another number on the number line. It may also be demonstrated as combining two piles of pennies together.
Taking a smaller number away from a larger number is called subtraction. This may be done by counting a number to the left from another number on the number line. It may also be demonstrated by breaking a pile of pennies in two smaller piles and taking one of those piles away.
Such opertions may help one develop a sense of estimating quantities without having to count each object.
By pairing pennies from a pile one may determine if they are even or odd. Numbers of pennies may also help one develop a sense of relative value, especially when they are presented as different coins. Here are some exercises in this subject for the kindergarten level.
LEVEL K5: NUMBERS & OPERATIONS
“Numbers and Operations” introduces the basic operations with numbers and how such operations may be executed with skill. That is the sense underlying the word ARITHMETIC (from arithmos number + techne skill).
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