If you're hunting for the use ten to subtract lesson 3.7 answer key, you're likely sitting at a kitchen table with a slightly confused kid and maybe feeling a bit stumped yourself. It's okay—most of us learned math by just "borrowing" or "regrouping" without really thinking about why we were doing it. This lesson, which is a staple in many elementary math curriculums like Go Math, takes a completely different approach. It's all about helping kids see the number ten as a "landmark" or a safe harbor to make mental math faster and easier in the long run.
The whole point of this lesson is to stop counting on fingers and start using logic. Instead of just memorizing that $13 - 9 = 4$, kids are taught to break the problem down into smaller, more manageable chunks. If you're looking for the answers to help your student through their homework, I've got the breakdown right here, along with the logic behind it so you can actually explain it when they give you that blank stare.
What Does "Use Ten to Subtract" Even Mean?
Before we get into the specific answers for lesson 3.7, we should probably talk about what this method actually is. It's basically a two-step dance. The goal is to get to the number 10 first, because subtracting from 10 is way easier than subtracting from 13, 14, or 15.
Think of it this way: if you have $15 - 7$, the "use ten" strategy asks you to think about how to get that 15 down to 10. You'd take away 5 first. But you weren't supposed to take away 5; you were supposed to take away 7. Since $7$ is made of $5$ and $2$, you take away that remaining $2$ from your $10$. Now you're at $8$.
It sounds like more work when you explain it in words, doesn't it? But for a kid's brain, it builds a "number sense" that eventually makes them a math wizard. They start seeing numbers as flexible things they can pull apart and put back together.
Step-by-Step for Lesson 3.7 Problems
In this specific lesson, students are usually given a subtraction problem and a visual aid, like a ten-frame. Here is how the logic works for the most common problems found in the use ten to subtract lesson 3.7 answer key worksheets.
Example Problem 1: 14 - 9
- Look at the first number: 14. We want to get to 10.
- Subtract to get to 10: $14 - 4 = 10$.
- Check the subtrahend: We need to subtract 9 total. We already subtracted 4. How much is left? $9 - 4 = 5$.
- Subtract the rest: $10 - 5 = 5$.
- Final Answer: 5.
Example Problem 2: 12 - 8
- Get to 10: $12 - 2 = 10$.
- Split the 8: Since we took away 2, we have 6 more to go (because $8 - 2 = 6$).
- Finish it off: $10 - 6 = 4$.
- Final Answer: 4.
Example Problem 3: 15 - 6
- Get to 10: $15 - 5 = 10$.
- Split the 6: We used 5 to get to ten, so we have 1 left to subtract ($6 - 5 = 1$).
- The final step: $10 - 1 = 9$.
- Final Answer: 9.
Why Parents Often Struggle with This Lesson
If you're feeling frustrated, you aren't alone. Most of us were taught the "stack 'em and whack 'em" method—standard algorithms where you cross out the number in the tens place and move a one over. It's efficient, sure, but it doesn't always help a child understand quantity.
When you're searching for the use ten to subtract lesson 3.7 answer key, you might notice that the worksheet asks the student to "show their work" by drawing circles or using a ten-frame. This is where things get messy. Kids often just want to write the answer, but the curriculum wants to see the path they took.
If your child is stuck, try using pennies or Cheerios. Lay out 13 items. Ask them, "How many do we need to move away to have 10 left?" They'll move 3. Then ask, "If we need to move 7 total, and we already moved 3, how many more do we need to move?" They'll see there are 4 more to go. It makes the abstract concept of "breaking apart a number" much more real.
Common Pitfalls and How to Fix Them
Even with an answer key in hand, kids might make a few recurring mistakes in Lesson 3.7. Here's what to look out for:
- Forgetting to subtract the second part: Sometimes a kid will do the first part ($14 - 4 = 10$) and then just stop and write 10 as the answer. Remind them that they're not done until they've used up the whole number they were supposed to subtract.
- Splitting the number wrong: If the problem is $13 - 5$, they might forget that they need to take away 3 to get to ten and instead try to take away 2. Always remind them: "The first goal is always to make a ten!"
- Confusion with addition: Occasionally, kids get their wires crossed and add the remaining digit to 10 instead of subtracting it. If they get $13 - 5 = 12$, you know they added that extra 2 back onto the 10 instead of taking it away.
The Mental Math Advantage
It might seem like a lot of steps for a simple subtraction problem, but there is a method to the madness. Once a child masters "using ten," they can start doing much harder math in their heads.
Think about a problem like $54 - 7$. A kid who knows the Lesson 3.7 strategy will think: $54 - 4 = 50$, and then $50 - 3 = 47$. Boom. Done. No pencil or paper required. That's the "secret sauce" of this curriculum. It's not about making simple subtraction harder; it's about making complex math easier later on.
Tips for Getting Through the Homework
If you're still looking at the use ten to subtract lesson 3.7 answer key and feeling overwhelmed, take a deep breath. Here are a few ways to make the homework session go smoother:
- Don't skip the drawings: If the page has boxes for ten-frames, use them. It feels tedious, but for a visual learner, it's the only way the "breaking apart" concept clicks.
- Use the phrase "Make a Ten": Consistency in language helps. If you keep saying "get to ten," it becomes a familiar mental trigger for them.
- Keep it short: This kind of mental heavy lifting is tiring for a 7 or 8-year-old. If they're getting frustrated, take a five-minute break and come back to it.
- Check the "Think Central" or online portals: Many schools use digital versions of these lessons that have "Personal Math Trainers." These can be a lifesaver if you need a quick video explanation of the specific problem on the page.
Real-World Examples to Practice
You don't have to wait for a worksheet to practice this. You can do it anywhere.
- "Hey, we have 12 apples. If we eat 4, how many are left? Let's take 2 away to have 10, then take the other 2 away."
- "You have 15 minutes of screen time. You've used 8. How many are left? Let's take 5 away to get to 10, then take away the other 3."
The more they hear this logic out loud, the less they'll need to rely on looking up an answer key. They'll start to internalize the "bridge to ten" and subtraction will become second nature.
In the end, Lesson 3.7 is just one small building block. It feels like a hurdle now, but once they "get" it, everything from multi-digit subtraction to basic algebra becomes a whole lot clearer. So, grab those crayons, fill in those ten-frames, and remember that you're building a foundation for a lifetime of being "good at math." You've got this!