Study Guide Math Unit—Numbers and Place Value Learning Targets At the end of this unit— 1) I can read, write, and model six-digit numerals and identify the place value positions, value of each digit, and the relationship of each place value position to the next. 2) I can round whole numbers, 9,999 or less, to the nearest ten, hundred, and thousand and represent my thinking using pictures, numbers, and words. 3) I can compare two whole numbers between 0 and 9,999, using symbols (<, >, or =) and words (greater than, less than, equal to). Vocabulary Place Value place value—the value of a digit based on its position in a number 5 , Ones 3 Tens Thousands 2 Hundreds Ten Thousands value—how much a number is worth Hundred Thousands The comma is critical! 4 8 6 The value of the “8” is 80. The value of the “5” is 5,000. digit—0, 1, 2, 3, 4, 5, 6, 7, 8, 9 standard form—writing a number using digits; example: 374,512 expanded form—writing a number using each number’s value example: 300,000 + 70,000 + 4,000 + 500 + 10 + 2 or (3 x 100,000) + (7 x 10,000) + (4 x 1,000) + (5 x 100) + (1 x 10) + (2 x 1) word form—writing a number using words period—a group of three digits in a number separated by a comma example: 374,512 374 is called the thousands period and 512 is called the units period whole number—the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. (counting numbers, no fractions) numeral—a digit, used alone or with others, to express a number Rounding Numbers round—write a number to the nearest ten, hundred, or thousand examples: 38 to the nearest ten = 40 238 to the nearest hundred = 200 1,238 to the nearest thousand = 1,000 7,286 7,286 to the nearest ten = 7,290 7,286 to the nearest hundred = 7,300 7,286 to the nearest thousand = 7,000 estimate—to give an approximate number or answer; to tell about how many Rounding Rule 6 9 rounded to the nearest ten 69 The circled digit is a 9, so the underlined digit is rounded up to the next ten—7 0 1. Underline the place value you want to round. 2. Circle the digit to the right. Is the circled digit a Is the circled digit a 1, 2, 3, or 4? 5, 6, 7, 8, or 9? The underlined digit stays the same. The underlined digit is rounded up. 4 and below… LET IT GO 5 and above… GIVE IT A SHOVE Comparing Numbers compare—decide if numbers are equal to (=), less than (<), or greater than (>) each other examples: 504 < 732 3,673 > 3,214 6,748 = 6,748 Examples of what each student will be able to do: Place Value Given a number, the student will write the number in standard form, expanded form, and word form. standard form—457,612 expanded form— 400,000 + 50,000 + 7,000 + 600 + 10 + 2 or (4 x 100,000) + (5 x 10,000) + (7 x 1,000) + (6 x 100) + (1 x 10) + (2 x 1) 400,000 50,000 7,000 600 10 + 2 457,612 word form—four hundred fifty-seven thousand, six hundred twelve (The student should also be able to read the number orally.) Rounding Numbers 7,612 rounded to the nearest ten = 7,610 7,612 rounded to the nearest hundred = 7,600 7,612 rounded to the nearest thousand = 8,000 Comparing Numbers Begin comparing the numbers in the thousands place. If they are the same, move on. 7,824 7,842 Next, look at the hundreds place. If they are the same, move on. 7,824 7,842 Then, look at the tens place. 7,824 7,842 The 2 is less than the 4, so 7,824 is less than 7,842. 7,824 < 7,842