Arithmetic | Class 7 Mathematics Notes

2.1 Simple Expressions

Arithmetic expressions are mathematical phrases involving numbers and operations such as addition (+), subtraction (-), multiplication (×), and division (÷). Each arithmetic expression has a value, which is the number it evaluates to. For example, the expression 13 + 2 evaluates to 15. Expressions can be read in different ways; for instance, 5 × 25 can be read as '5 times 25' or 'the product of 5 and 25'. The equality sign '=' is used to denote that an expression equals its value, e.g., 13 + 2 = 15. Different expressions can have the same value; for example, 10 + 2, 15 - 3, 3 × 4, and 24 ÷ 2 all equal 12. Comparing expressions is done by comparing their values using signs such as '=', '<', or '>'. For example, 10 + 2 > 7 + 1 because 12 > 8. Understanding expressions and their values helps in simplifying calculations and reasoning about numbers.

📊 Diagram: Figure on page 2 illustrating comparison of marbles between Raja and Joy; Figures showing arithmetic expressions and their values.

🧪 Activity: Fill in blanks to make expressions equal; arrange expressions in ascending order; compare expressions using >, <, = signs without complicated calculations.

🔗 Connection: This section introduces basic arithmetic expressions and comparison, leading to the next section on reading and evaluating more complex expressions involving brackets and order of operations.