3.2.1 Reflection & Practice: (Pages 40-41)

Multiplying a number by 0.1 shifts the decimal point one place to the left. For example, 21 x 0.1 = 2.1.

A sample is a subset of a population used to represent the whole population. It is often used when surveying is impractical.

2.1

Surveying a sample helps to gather data about preferences without needing to ask every student, making it more efficient.

100,000

2.1

Use the ratio from the survey to estimate for the larger population. For example, if 10 out of 30 students like soccer, then 450 students would have approximately 150 liking soccer.

Percentage = (Part/Whole) x 100.

Evaluating an expression means calculating its value based on the numbers and operations involved.

Multiplying a number by 10 shifts the decimal point one place to the right. For example, 0.21 x 10 = 2.1.