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Horizontal Subtraction Made Efficient and Understandable

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In this example, the standard horizontal algorithm is turned into a number line giving students a method of solving subtraction without regrouping nonsense. Students focus on the difference between the two numbers and not isolating single digits with regrouping.

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all right guys balls passed out today because he's so excited about this next method said he learned and your students will like this to now I'm not saying that they're going to like this because this is a blast and this is a lot of fun they're going to like this because they'll actually be able to the mathematics that is happening in this problem 25 - 17 we want to look at the difference between two numbers and when is rain in this format the last thing that is telling us or showing is is the we should be looking at the difference between these two numbers students are wondering okay which number goes on top and then I got to Kris Kross regroup rebar I'll go next door to my neighbor's house get some more pieces whatever your kids are written manipulative that they can do every single time they attempt this problem and the best part is after they do the 6 times they won't write anything down but the answer okay so we turn this into a number line and it's okay to go from right to left there's absolutely nothing wrong with that we're looking at space between the two numbers the measurement the difference between at the units between it we're not focusing on we have 25 apples and we ate 17 apples and who does that anyway let's just Watch What Happens here we have 17  18 19 20 21 22 23 425 and the answer is eight say I already use manipulatives to eventually  he'll find your students need to write down very little to assist them in solving this difference just like that I change 125 - 17th if you'll notice I was still at Seventeen I can't at 8 at the spot I was at 25 but now I'm 25 on the count by adding eight I'm going to add another hundred and get to 125 so hundred + 8 would be a hundred and hate and that's the difference between 17 and 125 and yes if I want to go into the thousands now keep moving forward can go right ahead and do that you'll love the learning that occurs when you try this with your students good

Listed in 3rd Grade

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Horizontal Subtraction Made Efficient and Understandable

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