Review Rounding Write & Evaluate Expressions Estimate Sums & Differences Addition & Subtraction

Find the Place Value and Round

Increase by one or stays the same Where do I look first? Round this number to the nearest hundred 368 Look at the number to the right of the action Action Increase by one or stays the same

Use rounding When the question asks you to estimate. Such as: “about how many”…? When an exact answer isn’t possible. When an answer is difficult to obtain. (Educated guessing for multiple choice)

Rounding Procedures 1. Draw an arrow pointing to the place you are rounding. (action) 2. Draw a dot (an eye) under the digit to the right of the place you are rounding.

Rounding Procedures 3. If the digit is 0-4, the number with the arrow stays the same. The rest of the numbers to the right change to 0’s. 4. If the digit is 5-9, the number with the arrow rounds up one. The rest of the numbers to the right turn to 0’s.

Rounding Rhyme Ut ohhh! 5,621 5620 Mark the place, Look to the right Four or less are out of sight Five and up Will buy one more, All those less, are out the door In those empty Right-hand spaces, Zeros keep the proper places Except in places less than a whole Such as the decimal case The last number is the last place Oh yea! I’m moving up Wahoo! 5,621 6,000 Every place to the right of the arrow changes to zeros No zero place holder for me 2.88 2.9

Round to the nearest hundreds place.

1-4 stay down 5-9 round up one Answer 4,600

Answer 4,700

Answer 4,600

Round 2,593, 672 to the nearest tens place. 1-4 stay down 5-9 round up one Answer 2,593,670

Round to the nearest tenth place.

1-4 stay down 5-9 round up one

Answer 4.700

Answer 4.600

Round each number to the place that has an arrow. 500 923,749,100,000 5,289 239.1 30

Practice Rounding 269 (tens) 2.98 (ones) 3,146 (tens) .912 (hundredths) 86,574 (ten thousands) 178.54 (hundreds) 411,990 (hundreds)

Answers 269 (tens) 2.98 (ones) 3,146 (tens) .912 (hundredths) 86,574 (ten thousands) 178.54 (hundreds) 411,990 (hundreds) 270 3 3,l50 .91 90,000 200.00 412,000

Round Numbers 64 873 491 652 957 203 684

Answers 64 873 491 652 957 203 684 60 870 or 900 490 or 500 650 or 700 960 or 1,000 200 680 or 700

Estimate Sums & Differences Round off both numbers then add or subtract. 55 + 61 = ? 60 + 60 = 120 691 – 54 = ? 700 – 50 = 650

Math Words Place-The position of a digit in a number. Value- The product of a digit multiplied by its place. Standard Form-The usual way to write a number Expanded Form-A way to write a number as a sum of the products of each digit and its place. Whole number-any one of the numbers 0, 1, 2, 3, 4, and so on.

Math Words Decimal-A number with one or more digits to the right of the decimal point. Equivalent decimals- Decimals that name the same number such as .4, .40, .400 Round-To find the nearest value of a number, based on the given place. Estimate-To find a number that is close to the exact answer. Variable-A symbol used to represent a number or numbers

Math Words Algebraic Expression - A variable by itself or a combination of one or more variables, one or more operations, and possibly one or more numbers such as n + 2 Evaluate or evaluation - To find the value of an expression by performing the operation or operations. For Example n = 3, n + 2 3 + 2 = 5

Practice