Exploring Grade 3 Module 2 Lesson 12 Concepts

Mrs. Walker teaches students how to round two-digit numbers to the nearest 10 using a vertical number line. The lesson includes examples with milliliters, centimeters, and minutes, demonstrating the process of identifying endpoints, midpoints, and determining proximity to round numbers accurately. Students are encouraged to practice and apply the rounding rules, especially when numbers are exactly halfway between two tens.

What is the first step in rounding numbers using a vertical number line?

• Draw brackets

• Label the endpoints

• Identify the midpoint

• Count all the numbers

To which number does 73 milliliters round to the nearest ten?

• 75 milliliters

• 60 milliliters

• 70 milliliters

• 80 milliliters

What keyword indicates that we are estimating or rounding a number?

• Exactly

• About

• Only

• Just

Which number is 38 milliliters closest to when rounded to the nearest ten?

• 35 milliliters

• 40 milliliters

• 45 milliliters

• 30 milliliters

What is the midpoint when rounding 61 centimeters to the nearest ten?

• 61 centimeters

• 60 centimeters

• 65 centimeters

• 70 centimeters

After identifying the midpoint, what is the next step in rounding 61 centimeters?

• Label it as six tens one one

• Count the spaces between numbers

• Find if it's more or less than halfway

• Draw the vertical number line

What rule is applied when a number is exactly halfway between two tens while rounding?

• Stay the same

• Round up

• Round down

• Choose randomly

If a number is exactly halfway between two rounding points, to which do we round?

• The lower number

• The higher number

• The exact number

• None of the above

What unit of measurement was used in the example for rounding minutes?

• Milliliters

• Centimeters

• Liters

• Minutes

What is the rounded value of 25 minutes to the nearest ten?

• 30 minutes

• 25 minutes

• 35 minutes

• 20 minutes