K-5 friendly lesson
One small step at a time.Read the idea, try the activity, and celebrate each win as you go.
Subtract 1-Digit from 2-Digit using Models (No Regrouping)
✂️ Erase the cubes! We can use Base-Ten block pictures to help us subtract small amounts without borrowing anything.
Do this: Read the concept below, then try the quiz or activity.
Lesson 54 of 186
Concept
Drawing pictures is the easiest way to see subtraction.
🎯 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: ___