Videos, stories and songs to help Grade 2 students learn how to add using the partial sums method and how to subtract using the trade-first subtraction method.

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**How to add using the partial sums method?**

- Starting from the left, add up the numbers in the hundreds place.
- Add up the numbers in the tens place.
- Add up the numbers in the ones place.
- Add up all the partial sums.

Some advantages of using the partial sums method:

- The method breaks down the addition process into clear, step-by-step calculations. This approach can help students avoid errors and maintain a structured method for solving problems..
- Partial sums method emphasizes the importance of place value. Students can clearly see how each place value contributes to the overall sum, reinforcing their understanding of the base-10 system.
- The partial sums method can be a precursor to the standard algorithm for addition. Understanding the partial sums method can make it easier for students to transition to the standard algorithm when they are ready.

**How to subtract using Trade-First Subtraction Algorithm?**

- Look at the digit in the 1s place. If subtracting these digits results in a negative number then trade 1 ten for 10 ones.
- Do the same for the 10s place, 100s place and so on.
- Subtract in each column.

3 digits + 3 digits using the partial sums addition method

Trade-First Subtraction Algorithm

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