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Good Afternoon!. Today our lesson will cover The Rules of Subtraction AND Subtraction of multi-digit numbers. 1.) Round 567 to the nearest hundreds place. 1): 600. 2.) Round 67,423 to the nearest thousands place. 2): 67,000. 3.) Round 4,897 to the nearest tens place. 3): 4,900.
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Good Afternoon! Today our lesson will cover The Rules of Subtraction AND Subtraction of multi-digit numbers 1.) Round567to the nearest hundreds place. 1): 600 2.) Round67,423to the nearest thousands place. 2): 67,000 3.) Round4,897to the nearest tens place. 3): 4,900 CONFIDENTIAL
Let's review what we learned in the last lesson. There are several properties of addition COMMUTITATIVE PROPERTY: We can change the order and the sum stays the same. EXAMPLE: 4 + 6 = 10 6 + 4 = 10 ASSOCIATIVE PROPERTY: We can change the groupingand the sum stays the same. EXAMPLE: 2 + (3+ 8) = 10 (2 + 3)+ 8= 10 IDENTITY PROPERTY: We can add zero and the sum stays the same. EXAMPLE: 7 +0 = 0 CONFIDENTIAL
We add numbers together by first LINING UP THE DIGITS Then we need to determine if we must REGROUP 7+5=12 so we must REGROUP 12 ones as 1 ten and 2 ones 1 197 + 35 This is how we regroup. 2 CONFIDENTIAL
Now, let's look at 0in subtraction. 13 - 0 = 13 • If we subtract 0 from any number, the difference is that same number. 57 - 57 = 0 • If we subtract a number from itself, the difference is 0. CONFIDENTIAL
Subtraction is similar to addition. • We need to line up the digits. • Often we need to regroup. CONFIDENTIAL
We look at a problem here. First, we must line up the digits. 3,776 - 879 Thousands Place Ones Place Tens Place Hundreds Place 3,776 - 879 = CONFIDENTIAL
We begin by subtracting the ones. In this case, we cannot subtract 9 from 6 so we need to do the following things : • ADD THEM TO REGROUP IT AS TEN ONES and THE EXISTING SIX ONES. • LOOK AT THE TENS PLACE AND BORROW A TEN 6 16 3,476 - 879 * 7 Now, we can subtract 9 from 16. CONFIDENTIAL
Next, we move to the tensplace. Once again, we need to regroup a hundredas 10tens since we cannot subtract 7 from 6. 16 3 6 16 3,476 - 879 9 7 We add our 10tensto the 6tens to get 16 tens. Now we can subtract 7 from 16. CONFIDENTIAL
Next, we move to the hundreds place. Once again, we need to regroup a thousand as 10 hundreds since we cannot subtract 8 from 3. 16 13 2 3 6 16 3,476 - 879 9 5 7 Now we can subtract 8 from 13. CONFIDENTIAL
Finally, we move to the thousands place. 16 13 3 2 6 16 3,476 - 879 2, 9 5 7 (879 has zero thousands even though it is not written there!) We subtract 0 from 2. CONFIDENTIAL
Remember that subtraction begins with the top number and starts in the ones place. It's 7 minus 5 27 5 - If the problem is written horizontally.... 156 - 78 the top numberis the number to the left of the subtraction sign. CONFIDENTIAL
Let's try one together. 345 - 68 277 Remember to begin in the onesplace. Do you need to regroup? Let's try another one. 4,135 - 1,762 2,373 CONFIDENTIAL
Addition and Subtraction are INVERSE OPERATIONS We can check our subtraction work by adding from the bottom up. 421 - 187 234 234 + 187 421 CONFIDENTIAL
Here are some problems for you to try. 6,394 - 2,587 4,521 - 976 3,807 3,545 5,623 - 3,652 1,971 CONFIDENTIAL
1.) Maria and her family are driving to the Grand Canyon for a vacation. The Grand Canyon is 678 miles from her home. So far, her family has driven 189 miles. How many more miles do they have left to drive? 1): 489 CONFIDENTIAL
2.) Steve is playing a video game and needs 100,000 points to win. He currently has earned 36,482 points.How many more points does he need? 2): 63,518 CONFIDENTIAL
3.) Fill in the boxes. input output 602 398 735 531 619 823 RULE: Subtract 204 CONFIDENTIAL
Problems 1.) 567 - 0 = 1): 567 2.) 467 - 259 = 2): 208 CHECK YOUR WORK CONFIDENTIAL
3): 00,000 3.) 56,789 - 56,789 = 4.) 802 - 788 = 4): 14 CHECK YOUR WORK CONFIDENTIAL
5.) 5,032 - 4,854 = 5): 178 CHECK YOUR WORK CONFIDENTIAL
Let's review what we learned today. Now, let's look at 0in subtraction. 13 - 0 = 13 • If we subtract 0 from any number, the difference is that same number. CONFIDENTIAL
And, 57 - 57 = 0 • If we subtract a number from itself, the difference is 0. Subtraction is similar to addition. • We need to line up the digits. • Often we need to regroup. CONFIDENTIAL
Remember that subtraction begins with the top number and starts in the ones place. It's 7 minus 5 27 5 - If the problem is written horizontally.... 156 - 78 the top numberis the number to the left of the subtraction sign. CONFIDENTIAL
Great job today! Congratulations!You worked hard! See you in the next session CONFIDENTIAL