Number (add/sub)

Hong Kong

Stage 2

Lesson

Now that you've had a chance to look at adding and subtracting up to 4 digit numbers, you can apply those same strategies to adding even larger numbers.

You may wish to review the lessons on place value before you begin. Then, watch the videos in the sections below. Keep notes of important things to remember.

In the video below, you'll see and hear about the algorithm for addition. An algorithm is a set of steps or a procedure that you can follow.

Remember!

- You can add in any order.
- Be sure to add numbers of the same place value.
- If a place value has a sum larger than 9, regroup and carry over to the next place value (Go to the lesson on regrouping to see more).

The video below discusses the algorithm for subtraction. Watch the video and see if you can describe the steps in your own words.

Remember!

- In subtraction, order matters. Subtract the second number from the first.
- Subtract numbers of the same place value.
- If you see a smaller number being subtracted from a larger one, regroup and borrow from a larger place value. (Go to the lesson on regrouping to see more).

Solve $50032+1700$50032+1700.

Solve $99999-6000$99999−6000.

Evaluate $57995-5005$57995−5005.