## Chapter 10

### Part 1: Home and School Investigation

Send the Letter to Family (PDF file) home with each child. Put the children in pairs once they have brought in the grocery store ads. Ask the children to find as many different ways that they can to combine two grocery store items and find the total cost of each combination. Ask them to record what they found. You may need to review that ¢ stands for cent and that 1 penny is worth 1¢.

### Part 2: Be an Investigator

A good time to do this investigation is after Lesson 6 on adding two-digit numbers.

#### Materials

- Investigator Worksheet (PDF file)
- yardsticks

#### Introducing the Investigation

Show the children a yardstick. Ask, **Does anyone know what this is?** In the discussion point out that it is an instrument that you can use to measure something that is up to 36 inches in length. Show children 1 inch on the yardstick.

Say, **Today you are going to measure the length of something with the yardstick. I would like you to find something that is longer than one yardstick but shorter than two yardsticks put end-to-end. I would like you to find the length of the object you have chosen and record what you have found on this worksheet.** Hold the worksheet for children to see.

Because the object is longer than the length of one yardstick, the children will need to take two measurements. For example, they might take a measurement of 36 inches and 14 inches for the length of a desk. They will need to add these two numbers together to get a measurement of the length of the desk.

Have a volunteer demonstrate how to measure an object. Point out that the “zero end” of the yardstick must line up with an end of the object. On the object, mark where the end of the yardstick is, then line up the “zero end” of the yardstick at the mark. Show how you can read the number on the yardstick that matches at the other end. Tell the children to just find the closest number if a number does not match up exactly with the end of the object.

#### Doing the Investigation

Observe the children as they are measuring. They learned how to measure in inches in Grade 1 but they may not have measured with a yardstick before. Make sure they are placing the yardstick correctly and reading the measurement correctly. When the children are finished, ask them to share what they measured and what they found to be the total length.

#### Extending the Investigation

Have children find other objects to measure and record the results.