increase & decrease

Increase means to become bigger in size.

eg 1 Increase $300 by $40 $300 + $40 = $340

eg 2 Increase $300 by 5% 5 ÷ 100 ✕  300 = 15 $300 + $15 = $315

eg 3 The Petrol Index price (below) was generally increasing between 2001 and 2007.

eg 4 The parabola (below) is increasing when x > 3 (x is greater than 3).

Decrease means to become smaller in size.

eg 1 Decrease $300 by $40 $300 - $40 = $260

eg 2 Decrease $300 by 5% 5 ÷ 100 ✕  300 = 15 $300 - $15 = $285

eg 3 On the Scatterplot below, the Exam Score is generally decreasing as the Number of Missed Classes increases.

eg 4 The parabola (below) is decreasing when x < 3 (x is less than 3).