GOAL 1 The student will be able to Read and write whole numbers in figures and words and know what each digit represents. FIRST TERM MATH CONTENTS FOR 5th GRADERS 2013-2014
GOAL 1 PLACE VALUE TO MILLIONS COMPARING AND ORDERING NUMBERS, NUMBER NAMES ADDING AND SUBSTRACTING MENTALLY MULTIPLES OF POWERS OF 10 MULTIPLIYING AND DIVIDING MENTALLY BY 10,100 AND 1000 ESTIMATING AND POSITIONING NUMBERS ON A 0-10 000 AND 0-1000 LINE ESTIMATING QUANTITIES ROUNDING TO THE NEAREST 1000 OR 100
Key vocabulary
Standard form vs. Expanded form
PLACE VALUE TO MILLIONS IDENTIFYING PLACE VALUE Numbers, such as 6,495,784 have seven digits. Each digit is a different place value. The first digit is called the millions ' place value. There are six millions in the number 6,495,784. The second digit tells you how many sets of one hundred thousand are in the number. The number 6,495,784 has four hundred thousands. The third digit is the ten thousands ' place. There are nine ten thousands The fourth digit is the one thousands ' place In this example is five The fifth digit is the hundreds ' place In this example is seven The next digit is the tens ' place. In this example is eight The last or right digit is the ones ' place In this example is four
T here are … Six sets of 1,000,000 Four sets of 100,000 Nine sets of 10,000 Five sets of 1000 Seven sets of 100 Eight sets of 10 4 ones 6,495,784 Therefore
PLACE VALUE TO MILLIONS
EXERCISES TO PRACTICE Question-1: In this number 5,458 . What number is in the tens place? Question-2: In this number 12,802 . What number is in the hundreds place? Question-3: In this number 359.210 . What number is in the thousandths places? Question-4: In this number 3,768,574. What number is in the millions place?
Word problem
EXERCISES TO PRACTICE
Solving the problem
EXERCISES TO PRACTICE
Going farther…
Let´s practice in class …
Solving it …
Adding / substracting mentally multiples of powers of 10
Adding / substracting mentally multiples of powers of 10
Adding / substracting mentally multiples of powers of 10 When the number that we are adding is a multiple of 1000… In case of substracting a multiple of powers of 10…
Examples adding / substracting multiples of powers of 10… EXERCISES TO PRACTICE
MULTIPLYING/DIVIDING MENTALLY BY 10, 100, 1000
PRACTICING IN THE CLASSROOM
PRACTICING IN THE CLASSROOM
ESTIMATING AND POSITIONING NUMBERS ON A 0-10 000 AND 0-1000 LINE
ESTIMATING AND POSITIONING NUMBERS ON A 0-10 000 AND 0-1000 LINE
ESTIMATING QUANTITIES Estimating is an important part of mathematics and a very handy tool for everyday life. Get in the habit of estimating amounts of money, lengths of time, distances, and many other physical quantities. In mathematics we often stress getting an exact answer. But in everyday life a few cents here or there are not going to make much difference ... you should focus on the dollars! Estimation is ... ... finding a number that is close enough to the right answer. You are not trying to get the exact right answer What you want is something that is good enough (usually in a hurry!)
ESTIMATING QUANTITIES Estimation can save you money . Always do a quick estimation of how much you should pay: Example: you want to buy five magazines that cost $1.95 each. When you go to buy them the cost is $12.25. Is that right? "five at $1.95 each is about 5 times 2, or about $10" so $12.25 seems too much! Ask to have the total checked.
ESTIMATING QUANTITIES Estimation can save you time (when the calculation does not have to be exact): Example: You want to plant a row of flowers. The row is 58.3cm long. The plants should be 6cm apart. How many do you need? "58.3 is nearly 60, and 60 divided by 6 is 10, so 10 plants should be enough." Estimation can save you from making mistakes with your calculator: Example: You are calculating 107 times 56, and the calculator shows this: 952.00 Is that right? "107 times 56 is a bit more more than 100 times 50, which is 5,000" Ooops ! you must have typed something wrong ... ... in fact you pressed 17×56 (you left out the zero), and without estimating you could have made a really big mistake!
ROUNDING TO THE NEAREST 1000/100 To round off whole numbers: Find the place value you want (the "rounding digit") and look to the digit just to the right of it. If that digit is less than 5, do not change the "rounding digit" but change all digits to the right of the "rounding digit" to zero. If that digit is greater than or equal to 5, add one to the rounding digit and change all digits to the right of the rounding digit to zero.
ROUNDING TO THE NEAREST 1000/100 EXERCISES TO PRACTICE
THANKS FOR YOUR ATTENTION HAVE A WONDERFUL REST OF DAY