Everyday mathematics grade 4 4.7 Thousandths Objective: to extend basic concepts and notation for decimals through thousandths Everyday mathematics grade 4

Math message Complete problems 1-3 in your workbook on page 94 You may use the base 10 blocks to help you. If 1 big cube = 10 flats, then 10 flats make a big cube. 1 flat is 1/10th of a big cube. 1 flat = 10 longs, 1 big cube must have 10 times as many longs; or 100 longs. 1 big cube = 100 longs; so 1 long is 1/100th of a cube. Since 1 big cube = 100 longs, and 1 long = 10 cubes, 1 big cube must have 10 * 100 cubes, or 1000 cubes. Since 1 big cube = 1000 cubes then 1 cube is 1/1000th of a big cube.

Page 125 Begin by thinking of 1 big cube as ONE. Imagine that you are going to trade 235 cubes for flats and longs so that you have as few base 10 blocks as possible. How many flats would we have? How many longs? How many cubes are left? 2 flats, 3 longs, 5 cubes

visuals If one big cube is ONE, then 235 cubes can be represented by the fraction 235/1000 or by the decimal .235. These are read 235 thousandths. (the decimal can also be read as point two three five)

0.235 5 cubes 0 big cubes 2 flats 3 longs The digit before the decimal point names the number of big cubes. The first digit names the number of flats, the second digit names the number of longs, and the third digit names the number of cubes.

Thinking skills Why would the fraction 64/ 1000 be written as a decimal .064? Explain your reasoning to a friend. What about 8/1000 ? How would it be written as a decimal?

Less than or greater to 1 If there are fewer than 1000 cubes, is the fraction (and it’s equivalent decimal) less than or equivalent to 1? Why? How many cubes are needed to show a number that is at least 1?

Page 125 Complete page 125 either independently or with a partner.

In your ISN Write these decimals in your ISN. .581 .072 .006 3.703 15.024 15.24 34.09 What is the WORD form for each decimal? (how would you SAY each one?)

Try these ones… Write these in your ISN and write its decimal equivalent next to it. 367 thousandths 51 thousandths 9 and 634 thousandths 3 thousandths 5 and 79 hundredths 7 and 8 tenths

Workbook pages 94 and 95 Solve problems involving the representation of numbers with base 10 blocks, with fractions and decimals. Compare the decimals. For problem 6, use the base-10 block symbols shown on page 94.

Math boxes 4.7 Complete the math boxes 4.7 on page 93 independently.

Homework Complete the decimal problems on page 126 as homework. (study link 4.7)

Enrichment Analyzing softball batting averages Page 127 Apply your knowledge of decimals in the thousandths by analyzing batting averages. To find a batting average, the number of ‘hits’ is divided by the number of ‘at bats’ and then rounded to the nearest thousandth.

Play base-10 exchange with a partner (page 459) The object of the game is to be the first player to make an exchange for 1 big cube. 1. the bank starts with 1 big cube, 20 flats, 20 longs and 20 cubes. 2- players take turns. A player rolls 3 dice, announces the sum and takes that number of cubes (thousandths) from the bank and places the on his/her mat. 3 – whenever possible, a player exchanges 10 cues (thousandths) for a long (hundredth) or 10 longs (hundredths) for a flat (tenth) from the bank. 4 – the first player to exchange 10 flats for a big cube wins.

World tour Math workbook pages 171-173, 176 and 177. Student reference books And pages 419-421 Look at the data for the remaining countries in Africa in the world tour section. Select a country that you are interested in and you might want to visit. Complete the Country Notes pages for this country. Choose a separate country than your classmates. Update your Route Log on page 171.