Download
1 / 5
50 likes | 229 Views
Date: _____________ Math 9/9H. Place Value Which position is a digit of a number occupying? E.g.: 1 975 462.328 1 is in the millions place 9 is in the hundred thousands place 7 is in the ten thousands place 5 is in the thousands place 4 is in the hundreds place
E N D
Date: _____________ Math 9/9H Place Value Which position is a digit of a number occupying? • E.g.: 1 975 462.328 1 is in the millions place 9 is in the hundred thousands place 7 is in the ten thousands place 5 is in the thousands place 4 is in the hundreds place 6 is in the tens place 2 is in the ones place 3 is in the tenths place 2 is in the hundredths place 8 is in the thousandths place
Date: _____________ Math 9/9H Rounding Rules • ONLY ROUND THE ANSWER (do NOT round steps!) • Only two choices: • leave the number the same (if the following digit is less than five) • Round the number up (if the following digit is five or greater) • Only round ONE digit in any number E.g.: round 75.6 to the nearest whole number (nearest “one”) • This number could become 75 OR 76 • To solve: look at the number to the RIGHT of the “ones” place
Date: _____________ Math 9/9H • To solve, look at the number to the RIGHT of the “ones” place: if that number is less than five, leave the answer as 75; if that number is 5 or greater, round the answer up to 76. • So the correct answer is: 76! Examples to try: • Round 43.672 to the nearest TENTH 43.7 • Round 0.434 to the nearest HUNDREDTH 0. 43 • Round 12 346 to the nearest HUNDRED 12 300 • Round 869 942 to the nearest TEN THOUSAND 870 000
Date: _____________ Math 9/9H Estimating • Use rounding on all terms to make an educated guess of the answer E.g.: 47 x 104 -> round to 50 x 100 ~ 5000 actual answer: 4888 • Do the “actual calculation” to check if your estimate is close • Estimating is useful when checking if you answer seems “reasonable” E.g.: 89 x 201 -> round to 90 x 200 ~ 18 000 if your answer came to 1780, you would be suspicious you have made an error actual answer: 17 889
Date: _____________ Math 9/9H Definitions • Sum: the answer when you are adding • Difference: the answer when you are subtracting • Product: the answer when you are multiplying • Factors: the things you multiply to get the product • Quotient: the answer when you are dividing • Divisor: the number you are “dividing by” (bottom number of a fraction) • Dividend: the number you are “dividing into” (top number of a fraction)
