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Mr. Olson’s Computer Tutor. Trade-first Subtraction in the Tens and Hundreds Place. Spot the Trade…. Which one of these 2 problems do we need to use trade first to solve? Write your answer on number one on your paper!. 234. 286. -. -. 86. 34. ____. ____. A. B. Spot the Trade….
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Mr. Olson’s Computer Tutor Trade-first Subtraction in the Tens and Hundreds Place
Spot the Trade… Which one of these 2 problems do we need to use trade first to solve? Write your answer on number one on your paper! 234 286 - - 86 34 ____ ____ A B
Spot the Trade… The digits in the TENS and ONES place in the top number are smaller than the bottom digits. If you said problem A , you spotted the trade! 234 - 86 ____
Spot the Trade… Let’s start in the ONES place. We can see right away that we will need to trade with our neighbor in the TENS place. 234 - 86 ____
Spot the Trade… Right now, we have 3 TENS. We need to take one of those TENS over to the ONES place. 234 - 86 ____
Spot the Trade… When we take one of the TENS away, it leaves us with 2 TENS. We add the TEN that we took to what we already had in the ONES place. 234 - 86 ____
Spot the Trade… This digit is still smaller than the bottom digit. 2 Now, we have 14 ones and 2 tens. Look closely! We can subtract the digits in the ONES place, but we can’t subtract the digits in the TENS place. 14 234 8 - 86 ____
Spot the Trade… 2 We need to trade with our neighbor in the HUNDREDS place so that we can get enough TENS to subtract. 14 234 8 - 86 ____
Spot the Trade… 2 When we take one of the HUNDREDS away, we are left with 1 HUNDRED. We bring those 10 TENS over to the TENS place and add them to the two TENS we have left. 14 234 8 - 86 ____
Spot the Trade… 12 2 1 Now we can subtract the digits in the tens place and the digits in the hundreds place. 14 234 1 4 8 - 86 ____
Let’s practice! Work on the next two problems on your own. They will be number 2 and number 3 on your paper. 2. 3. 343 551 - - 286 75 ____ ____
Let’s practice! Check your work! Make sure you followed all of the steps. 13 14 3 4 2 4 13 11 2. 3. 551 343 - - 286 75 ____ ____ 268 265
Show what you know! Now, work on these next two problems. They will be numbers 4 and 5 on your paper. When you are finished, leave the computer and hand your paper to Mr. Olson. 4. 5. 165 648 - - 179 98 ____ ____