Mod27 representing hundredths - eWorkshop

1 representing hundredths hundredths on 10x10 Grids Materials overhead projector overhead transparency of 10x10 Grid (attached). overhead transparency of Shaded 10x10 Grids (attached). copies of representing hundredths on 10x10 Grids worksheet 1 per student Activity Display an overhead transparency of a 10x10 grid. Discuss the arrangement of squares in rows and columns there are 10 rows with 10 squares in each row. Establish that there are 100 squares in the entire grid and that each square is one hundredth of the grid. Display and discuss, one at a time, the other 10x10 grids on the overhead transparency. For each grid, ask: How many hundredths are shaded? How can you determine the number of hundredths quickly, without counting each square individually? Is ___ hundredths a quantity that is close to 0, close to , or close to one whole? How do you know? For the grids in which 20 hundredths and 60 hundredths are shaded, ask: How many tenths are equal to 20 hundredths (60 hundredths )?

2 How do you know? . Extend the activity by having students work individually on the representing hundredths on 10x10 Grids worksheet. Students can share their work with a partner. Decimal Numbers grade 4 to grade 6 1 Queen's Printer for Ontario, 2006. representing hundredths hundredths Wheels Materials copies of the hundredths Circles (duplicated from the attached copy onto two different colours of paper) 2 copies (1 of each colour) per student scissors for each student Activity Provide each student with two copies of a hundredths circle, duplicated onto different colours of paper. Have students assemble the hundredths wheels by cutting out the circles, cutting along the dotted line, and inserting one circle inside the other. Ask students to rotate sections of the hundredths wheel to show different hundredths ( , 50. hundredths , 10 hundredths , 25 hundredths , 90 hundredths ). Discuss whether each quantity is a large or small part compared to the whole wheel ( , 10 hundredths is a small part of the whole, 90 hundredths is a large part of the whole).

3 Also discuss relationships between fractions and decimal numbers ( , 25 hundredths is equal to one fourth, 50 hundredths is equal to one half) and between tenths and hundredths ( , 10 hundredths equals 1 tenth, 90 hundredths equals 9 tenths). Decimal Numbers grade 4 to grade 6 2 Queen's Printer for Ontario, 2006. representing hundredths hundredths on a Number Line Materials number line, 1 m long, drawn on the board metre stick (calibrated in centimetres). Activity On the board, draw a line that is 1 m long. Label 0 and 1 at opposite ends. 0 1. Explain that the line represents a number-line segment from 0 to 1. Ask students to estimate the positions of one half, one fourth, and three fourths on the line segment. Have students explain how they made their estimates. Ask the students to imagine that the line segment is divided into 100 equal parts. Establish that each part is one hundredth of the line segment and that there are 100 hundredths between 0 and 1.

4 Next, ask students to estimate the location of 50 hundredths on the line segment. Give them a moment to think about the question individually. Then invite a student to draw an arrow to indicate the approximate position of 50 hundredths . Ask the student to explain how he or she determined the number's location. Show a metre stick and remind students that there are 100 centimetres in a metre. Discuss the idea that each centimetre is one hundredth of a metre and have students locate 50. hundredths (50 centimetres) on the metre stick. Ask how the metre stick could be used to check estimated positions of numbers on the line segment. Hold the metre stick directly below the number segment and discuss the proximity of the estimated position of 50 hundredths to its actual location. Repeat by having students estimate the location of other hundredths ( , 25 hundredths , 1 hundredth, 95 hundredths , 40 hundredths ). For each number, ask students to explain how they made their estimate and to check their estimates using the metre stick.

5 Next Step Have students estimate numbers greater than 1 (150 hundredths , 200 hundredths , 225. hundredths , etc.). Decimal Numbers grade 4 to grade 6 3 Queen's Printer for Ontario, 2006. 10x10 Grid Decimal Numbers grade 4 to grade 6 4 Queen's Printer for Ontario, 2006. Shaded 10x10 Grids Decimal Numbers grade 4 to grade 6 5 Queen's Printer for Ontario, 2006. representing hundredths on 10x10 Grids Shade the grid to show a quantity Shade the grid to show a quantity that is close to 1. that is close to 0. I shaded _____ hundredths . I shaded _____ hundredths . Shade the grid to show a quantity Shade the grid to show a quantity 1 1. that is close to . that is close to . 2 4. I shaded ____ hundredths . I shaded _____ hundredths . Shade the grid to show a quantity Shade the grid to show a quantity 3 7. that is close to . that is close to . 4 10. I shaded _____ hundredths . I shaded _____ hundredths . Decimal Numbers grade 4 to grade 6 6 Queen's Printer for Ontario, 2006.

6 hundredths Circle Decimal Numbers grade 4 to grade 6 7 Queen's Printer for Ontario, 2006.