It's time to practice subtracting greater (larger) numbers. For this activity, you'll need the Internet, two pieces of construction paper, and a black marker. In place of the Internet, you can use a daily newspaper or advertising inserts with ads showing products for sale.
Imagine you have been working hard to earn money. You have saved $1,500. This will be your greater number. There are many things that you would like to buy, but you don't want to spend all of your money. You would like to keep at least $1,000 for your savings.
When we buy something, we are giving up money, so we subtract that amount from what we had before. In this activity you will subtract items to see what you can buy with your earnings.
Make a list of items you would like to buy with your $1,500. Write your list on a piece of construction paper. Then go to the Internet or ads to find out the prices of these items. Write the price next to each item.
Decide the three items that you want to buy the most. Add up the prices.
Say you want to buy three CDs for $45, a new bicycle for $228, and tickets for you and a friend to a baseball game for $60. You will spend $333.
Take the second piece of construction paper and use the marker to write this problem:
You need to solve it to know how much money you have left after these purchases.
When you work out this problem, you get 1,167 as the answer. That means that you still have $1,167 left!
Remember that you wanted to save at least $1,000. If you want to buy a fourth item, you have to subtract again.
You can still spend $167 on another item from your list and still save $1,000. Or, you can save all $1,167!
Ready to move on to the next lesson?
Four Digit Place Value Subtraction
