Objective: Using a Ruler to Measure to the Nearest Inch

Objective: Using a ruler to measure to the nearest ¼ inch

Materials: tagboard 13 inches long; standard rulers, colored pencils

Lesson:  Hand out tagboard to each student  If we look at the inches side of your ruler, what do you notice? (there are big numbers and then tick marks in between each one)  Have students move about a thumb space in from the end of their tagboard and make a linear mark. Now, if I want to mark off the inches from this mark, how do I do this? (line up the edge of the ruler with the mark).  Make a mark and label each of the marks with the corresponding number. (be sure students put a 0 on the end mark and label through 12).  What if I wanted to make ½ inch marks? What would that look like? What mark on my ruler would I use to mark off the ½ inch marks? (have students pair-share with a partner and then demonstrate this on the model ruler) Have students make a ½ mark on each inch that they have marked on the tagboard.  What do you notice on your ruler about the size of the marks that indicate ½ inch? (they are shorter than the inch markings)  Continue with ¼ inch. What does ¼ inch mean? (we’ve divided that space into 4 equal parts). Discuss with students why the markings are labeled ¼, then ½, then ¾. Why are the denominators changing? (because another way of writing ½ is 2/4 – so it really goes ¼, 2/4, ¾)  How would I write the number 3 and ¼? 3 ¼ - have students practice this a few times.  Last, have students color each inch section a different color (or alternate between 2 colors)  We are going to use our new ruler to measure things to the nearest ¼ inch. What do you think to that means? (similar to rounding, you go to the closest mark)  Hand out worksheet. Discuss what each item in the table means. Specify which direction you want students to measure their books and desks. Also, be sure that students understand what the span of their hand is. Have students work with a partner to measure the items on the sheet to the nearest ¼ inch, using the ruler they have just made.  Bonus: if finished early, have students use the metric side of a store bought ruler and measure to the nearest cm. Challenge students to find a relationship between the inch measurement and the cm. measurement. Name: ______

Measurement to nearest Measurement to the Item ¼ inch nearest cm

Math Book

Desk Top

Span of your hand

Pencil

Your choice:

Journal Question: Which unit has a greater number in front of it – cm or inches? Explain why.

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