Subtract 1-Digit from 2-Digit using Models (No Regrouping)
āļø Erase the cubes! We can use Base-Ten block pictures to help us subtract small amounts without borrowing anything.
Concept
Drawing pictures is the easiest way to see subtraction. šÆ **The "Cross It Out" Method:** **Example: 28 - 5 = ?** 1. **Draw the starting number (28):** Draw 2 long Tens-Rods and 8 little Ones-Cubes. | | . . . . . . . . 2. **Subtract the second number (5):** Look at the little Ones-Cubes. You need to take 5 away! 3. **Cross them out:** Put an 'X' over 5 of the little dots. | | X X X X X . . . 4. **Count what is left!** You still have 2 Tens-Rods. You have 3 Ones-Cubes. 5. **Answer:** **23**! You didn't even have to touch the Tens-Rods! They stayed perfectly safe.
Try it
Cross out the cubes! **Instructions:** Imagine the big blocks and little blocks for the first number. Cross out the little blocks to find the answer. **Problem 1: 37 - 4 = ?** * Draw 3 Tens and 7 Ones. * Cross out 4 Ones! * How many Tens are left? ___ How many Ones are left? ___ * Answer: ___ **Problem 2: 59 - 8 = ?** * Answer: ___ **Problem 3: 16 - 3 = ?** * Answer: ___ **Problem 4: 45 - 2 = ?** * Answer: ___