161×5

161 × 5 is a multiplication of two integers, 161 and 5. The product is 805.

This can be obtained by several equivalent approaches. One straightforward method uses decomposition: 161 × 5 = (160 + 1) × 5 = 800 + 5 = 805. Another method uses the identity that multiplying by 5 equals multiplying by 10 and dividing by 2: 161 × 5 = 1610 ÷ 2 = 805. A third way highlights place value: 161 × 5 = 500 + 300 + 5 = 805, since 161 = 100 + 60 + 1, and 5 × each part sums to 500, 300, and 5 respectively.

Factorization considerations show that 161 factors into 7 × 23, so 805 equals 5 × 7 × 23. This illustrates basic properties of multiplication, including the distributive property over addition and the commutativity of multiplication (161 × 5 = 5 × 161).

In a broader context, multiplying by 5 is a common mental-math operation in decimal arithmetic. The result of 161 × 5 ends with the digit 5, reflecting the rule that multiples of 5 end in 0 or 5. The calculation demonstrates straightforward arithmetic that underpins more complex multiplication and serves as an example of how factors combine to form a product.