1. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. Learning Objective Name _____________________________ Today, we will subtract numbers. CFU What are we going to do today? What are we going to subtract? Activate (or Provide) Prior Knowledge Today, we are going to subtract numbers. We are going to subtract numbers. Students hold up one hand and count your fingers. How many fingers did you count? Now put one finger down and count how many fingers are left up. How many fingers did you count? CFU Teacher models first, then students. Students, you already know we can take things away. We can do the same thing with numbers. This is called subtraction. Today, we will subtract numbers.

2. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. Concept Development To subtract means to take away.  The “  ” sign is called the “minus” sign. It tells us to subtract the numbers.  The = sign stands for equals. Example: There are 3 slices of pizza. If Billy eats 1 slice how many slices of pizza are left? 1 slice of pizza subtracted from 3 slices of pizza equals 2 slices left over. CFU What does subtract mean? To subtract means ____________. What is it called when we take away numbers? ______________. Which numbers are subtracted correctly? A. 2 – 1 = 3 B. 2 – 1 = 1 to take away. Subtract – = – = We say, “Three minus one equals two.”

3. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. Importance To subtract means to take away. It is important to be able to subtract numbers so you can: 1.count faster. 2.know how many objects are left over. 4 pieces I eat 1 I have 3 left CFU Does anyone else have another reason why it is important to be able to subtract numbers? (pair-share) Why is it important to be able to subtract numbers? You may give me one of my reasons or one of your own. Which reason means more to you? Why?

4. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. Skill Development/Guided Practice Name________________________ Step #1: Find the first number of the subtraction fact on the number line. Step #2: Read the second number. a. Subtract by counting down this many times. Step #3: Read the fact aloud. 0 1234 56 789 10 My Subtraction Facts for 1, 2, and 3 CFU How did I know where the first number was on the number line? How did I subtract using the second number? How did you know where the first number was on the number line? How did you subtract using the second number?

5. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. My Subtraction Facts for 4, 5, and 6 CFU How did I know where the first number was on the number line? How did I subtract using the second number? How did you know where the first number was on the number line? How did you subtract using the second number? Skill Development/Guided Practice (continued) Name________________________ Step #1: Find the first number of the subtraction fact on the number line. Step #2: Read the second number. a. Subtract by counting down this many times. Step #3: Read the fact aloud. 0 1234 56 789 10

6. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. My Subtraction Facts for 7 and 8 Skill Development/Guided Practice (continued) Name________________________ CFU How did I know where the first number was on the number line? How did I subtract using the second number? How did you know where the first number was on the number line? How did you subtract using the second number? Step #1: Find the first number of the subtraction fact on the number line. Step #2: Read the second number. a. Subtract by counting down this many times. Step #3: Read the fact aloud. 0 1234 56 789 10

7. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. My Subtraction Facts for 9 and 10 CFU How did I know where the first number was on the number line? How did I subtract using the second number? How did you know where the first number was on the number line? How did you subtract using the second number? Skill Development/Guided Practice (continued) Name________________________ Step #1: Find the first number of the subtraction fact on the number line. Step #2: Read the second number. a. Subtract by counting down this many times. Step #3: Read the fact aloud. 0 1234 56 789 10

8. DataWORKS Educational Research (800) 495-1550 www.dataworks-ed.com © 2011 All rights reserved. Comments? feedback@dataworks-ed.com 1 st Grade Number Sense 2.1 Know the addition facts (sums to 20) and the corresponding subtraction facts and commit them to memory. Lessons are to be used by EDI-trained teachers only. Blank Page