Warm Up • Which Standard for Mathematical Practice do you feel is most important? Why do you think it is the most important? Powers of Ten Alignment Lesson 2 20 200 2,000 • Take a look at the numbers above!! • How are they alike? • How are they different? 2 20 200 2,000 • Let’s use base ten pieces to model these numbers. 2,000 200 20 2 2 x 1,000 = 2,000 2 groups of 1,000 2 x 100 = 200 2 groups of 100 2 x 10 = 20 2 groups of 10 2x1=2 2 groups of 1 2,000 200 20 2 2 x 1,000 = 2,000 2 groups of 1,000 2 x 100 = 200 2 groups of 100 2 x 10 = 20 2 groups of 10 2x1=2 2 groups of 1 •In which direction did the digit 2 move when we multiplied by 10 (instead of 1)? •To the left, the 2 moved from the ones place to the tens place •How many places did the 2 move in this direction? •One place •In which direction did the digit 2 move when we multiplied by 100 (instead of 10)? •To the left, the 2 moved from the tens place to the hundreds place •How many places did the 2 move in this direction? •One place •In which direction did the digit 2 move when we multiplied by 1,000 (instead of 100)? •To the left, the 2 moved from the hundreds place to the thousands place •How many places did the 2 moved in this direction? •One place Math Talk Can you create a general rule or relationship for what we’ve just observed? • Rule: A digit in one place represents ten times as much as it represents in the place to its right. -or• A digit in one place represents 1/10 of what it represents in the place to its left. Think about this… • Ten of the smaller place value make one of the next place value to the left. Therefore a digit in one place represents ten times as much as it represents in the place to its right. For example: • 10 ones make 1 ten (10 units make 1 rod) so 20 is ten times as big as 2 and the value of the 2 is ten times as much in 20 as it in 2 • The same is true for 200, 10 tens make 1 hundred (10 rods make 1 flat) so 200 is ten times as big as 20 and the value of the 2 in two hundred is ten times as much as it is in 20 X 3 30 300 3,000 2 2x3 =6 2 x 30 = 2 x 3 x 10 = 6 x 10 = 60 2 x 300 = 2 x 3 x 100 = 6 x 100 600 2 x 3,000 = 2 x 3 x 1,000 = 6 x 1000 = 6,000 20 20 x 3 = 2 x 10 x 3 = 6 x 10 = 60 20 x 30 = 2 x 10 x 3 x10 = 6 x 100 = 600 20 x 300 = 2 x10 x 3 x 100 = 6 x 1,000 = 6,000 20 x 3,000 = 2 x 10 x 3 x 1,000 = 6 x 10,000 = 60,000 200 200 x 3 = 2 x 100 x 3 = 6 x 100 = 600 200 x 30 = 2 x 100 x 3 x 10 = 6 x 1,000 = 6,000 200 x 300 = 2 x 100 x 3 x 100 = 6 x 10,000 = 60,000 200 x 3,000 = 2 x 100 x 3 x 1,000 = 6 x 100,000 = 600,000 2,000 2,000 x 3 = 2 x 1,000 x 3= 6 x 1,000 6,000 2,000 x 30 = 2 x 1,000 x 3 x 10 = 6 x 10,000 = 60,000 2,000 x 300 = 2 x 1,000 x 3 x 100 = 6 x 100,000 = 600,000 2,000 x 3,000 = 2 x 1,000 x 3 x 1,000 = 6 x 1,000,000 = 6,000,000 What patterns do you see in each row and column? What general rules(s) for multiplying numbers with zeros can you create? Homework Day 2, “Powers of Ten Journal Prompt”