Unit 2 Estimation and Computation

Use the following number 5, to answer questions 1 and What digit is in the hundreds place? a. 5 b. 6 c. 3 d What digit is in the tenths place? a. 2 b. 3 c. 1 d. 7

3. Without using computation, what is 34 * 10,000? a. 34, 000 b. 3, 400 c. 340, 000 d. 3, 400, 000

Lesson 2-1: Place Value

Lesson 2-1: Rules of Rounding underline place value you are rounding to look one place to the right 5 or more raise the score 4 or less let it rest all numbers to the left of underlined number stays the same Examples: 4,827 rounded to the nearest ten is 4,830 4,827 rounded to the nearest hundred is 4,800 4,827 rounded to the nearest thousand is 5,000

number ,000 3, ,673 75, ,286 4, ,810.8 Round each number to the nearest... 6,811 4,250 6,8106,8007,000 4,2504,200 4,000 3,286 75,486 12,673 3,471 3,2903,300 75,49075,50075,000 12,670 12,70013, 000 3,470 3,5003,000

Number , Round each number to the nearest XX X X ,4004,4104,409 4,

Classwork: 1. Begin rounding and place value packet If time: 2. Math Box 2- 1 (p. 31) 3. Extra Credit

Standard NotationExpanded Notation Lesson 2-2: Expanded Notation , ,

Lesson 2-2: Partial Sums Addition Keep an open mind. When working on your own, you only need to use this strategy for one problem

Remember to line up the decimal points

Classwork: 1. Complete journal page If time: 2. Math Box 2-2 (p. 34) 3. Extra Credit

Lesson 2-3: Trade First Keep an open mind. When working on your own, you only need to use this strategy for one problem

= = =

Classwork: 1. Complete journal page 35 If time: 2. Math Box 2-3 (p. 36) 3. Extra Credit

Lesson 2-4: Addition and Subtraction Number Stories Number SentencesOpen Number Sentences Use math symbols instead of words can be true or false must use a relation symbol =, must use an operational symbol +, - *, ÷ Examples = 4 true 6 * 4 > true 3 > 9 false contain a variable -letter that represents a number Examples Solution (variable equals) Answer (unit label) 5 + B = 12 B = 7 D ÷ 3 = 8 3 * 4 = V C = 60 D = 24 V = 12 C = 60

At breakfast, the temperature outside was 47˚F. By lunchtime, the temperature was 63˚F. How many degrees warmer was it by lunchtime? Open number sentence Solution: Answer: Mary had $32.50 in her savings account. After she withdrew some money, she had $17.25 left. How much money did she withdraw? The school library has 486 fiction books and 321 non fiction books. How many books does the library have in all? Open number sentence Solution: Answer: Open number sentence Solution: Answer: Mr. Snow is 49 years old. Her son, Kevin, is celebrating his 24th birthday today. Mr. Snow is 6 years older than Mrs. Snow. How old was Mrs. Snow when Kevin was born? Open number sentence Solution: Answer:

Classwork: 1. Complete journal page 37 & 38 If time: 2. Math Box 2-4 (p. 39) 3. Extra Credit

Lesson 2-5: Statistical Landmarks Minimum: lowest number Maximum: highest number Range: highest number minus the lowest Mode: the number that occurs most often. There can be one mode, more than one or no mode. Example: 3, 4, 4, 5, 6, 6 Example: 1, 5, 4, 3, 3 Example: 3, 4, 5, 6,

Median: the middle number when all the numbers are arranged in numerical order. Mean: the average - add all the numbers, divided by the number of numbers you have. Example: 7, 8, 3, 1, 5 Example: 1, 2, 5, 7, 8, 9 Example: 3, 4, 5, 6,

Practice: 10, 7, 1, 2, 10, 6, 4, 8 minimum maximum range mode median

Classwork: 1. Complete journal page If time: 2. Math Box 2-5 (p. 42) 3. Extra Credit

Displaying Reaction Time in Line Plots Right Hand Reaction Times (seconds)

Displaying Reaction Time in Line Plots Left Hand Reaction Times (seconds)

Lesson 2-7: Magnitude Estimates Magnitude Estimates are very rough estimates to a problem. Round both numbers to greatest place. 1’s1’s10s100‘s1,000s10,000s 56 * * * 215 1’s1’s10s100‘s1,000s10,000s 1’s1’s10s100‘s1,000s10,000s

13 * * * s0.1s1’s1’s1s10s 0.01s0.1s1’s1’s1s10s 0.01s0.1s1’s1’s1s10s

Make a magnitude estimate 73 * * * * *3.9 1’s1’s10s100‘s1,000s10,000s 1’s1’s10s100‘s1,000s10,000s 1’s1’s10s100‘s1,000s10,000s 0.01s0.1s1’s1’s1s10s 0.01s0.1s1’s1’s1s10s 70 * 30 = 2,100 10* 700 = 7,000 20* 2 = * 100 = 10,000 3 * 4 = 12

Lesson 2-8: Traditional Multiplication - Whole Numbers 53 * 4 = ______19 * 5 = ______ 24 * 7 = ______

562 * 4 = ______104 * 3 = ______ 710 * 9 = ______

38 * 21 = ______97 * 34 = ______ 52 * 31 = ______

284 * 91 = ______ 804 * 37 = ______ 619 * 96 = ______

2-8A - Traditional Multiplication - Decimals 53 * 0.8 = ______9.3 * 0.7 = ______ 494 * 0.6 = ______349 * 0.3 = ______

504* 0.2 = ______6.4 * 8.6 = ______ 7.5 * 1.7 = ______239 *.28 = ______

Lesson 2-10: Powers of ten