Strategies for subtracting more complex decimals with tenths

TL;DR

Learn different strategies for subtracting decimals, such as breaking the numbers into ones and tenths, visualizing on a number line, and subtracting using whole numbers and fractions.

Transcript

• [Instructor] Do some more examples subtracting decimals. So let's say we wanna figure out what two minus 1.2 is. Pause this video and see if you can calculate this. So there is multiple ways to tackle this. One way is you could say, "Look, this is the same thing "as two minus one "minus 2/10." This is two minus one and 2/10. So we're subtracting ... Read More

Key Insights

• #️⃣ There are multiple strategies for subtracting decimals, such as breaking them into whole numbers and fractions or visualizing them on a number line.
• #️⃣ Subtracting whole numbers first can make the process easier and more straightforward.
• 🫥 Adding tenths to a smaller decimal can help make the subtraction easier, especially when visualizing it on a number line.
• 💦 It is important to find a strategy that works best for each individual, whether it is mental calculation or using paper and pencil.

Questions & Answers

Q: How can you subtract decimals by breaking the numbers into whole numbers and fractions?

By breaking the numbers into whole numbers and fractions, you can subtract the whole numbers first and then subtract the fractions. For example, 2 - 1.2 can be seen as 2 - 1 - 2/10, which equals 0.8 or 8/10.

Q: How can you subtract decimals using a number line?

You can visualize the numbers on a number line, subtract each part separately, and find the difference. For example, starting at 2, subtracting 1 and 2/10 will get you to 8/10 or 0.8.

Q: What is the difference between 3.8 and 1.5?

The difference between 3.8 and 1.5 can be calculated by subtracting the whole numbers and then subtracting the fractions. In this case, it equals 2.3.

Q: How can you subtract decimals by adding tenths?

If you have to subtract a smaller decimal from a larger decimal, you can add tenths to the smaller decimal to make it easier. For example, 5/10 - 8/10 can be rewritten as 1 + 5/10 - 8/10, which equals 7/10 or 0.7.

Summary & Key Takeaways

• One way to subtract decimals is to break the numbers into whole numbers and fractions, subtract the whole numbers first, and then subtract the fractions.

• Another strategy is to visualize the numbers on a number line and subtract each part separately.

• You can also subtract decimals by thinking about how many tenths you need to add to one number to get to the other.