MODULE 4 Lesson 4. Objective Add and subtract multiples of 10 and some ones within 100.
Transcript of MODULE 4 Lesson 4. Objective Add and subtract multiples of 10 and some ones within 100.
MODULE 4Lesson 4
Objective
•Add and subtract multiples of 10 and some ones within 100.
Place Value
• Say the number. • What digit is in the tens place? • What’s the value of the 7? • State the value of the 1. • State the place of the 4. • Let’s try some more by asking the same questions.
174
258 734 860 902
Making a Ten Drill
• 7 + ___ = 10 • Let’s find missing parts to make ten. If I say 7, you would
say 3. • Ready? 7. • Say the number sentence. • Let’s try some more numbers:
23 27 42 48 58
4 3 7 17 13
Making the Next Ten to Add
• When I say, 9+4, you say 10+3. • Ready? 9+4. • What’s the answer?
• Let’s try some others:
19+4 8+5
48+3
18+3
8+3
59+6
29+6
19+6
9+6
79+4
49+4
29+4
67+4
17+4
7+4
27+6
17+6
7+6
88+5
18+5
Concept Development• There are 5 yellow cubes. How many
linking cubes am I showing in this stick? • How many in this stick? • What is the difference between 8 and 5? • What number sentence could I use to
represent the difference between 8 and 5?
• 8–5=3.
Concept Development Continued
• Has the difference changed? • But what new number sentence can I use to represent the difference between my two sticks?
• 9–6=3. • Is the difference still 3? • YES!
Concept Development Continued• If I add more to each bar. Did the
difference change? • Let’s test this idea. When we add the
same amount to each number in a subtraction sentence, the difference stays the same.
• Now let’s try this with a new problem. 34 – 28
• Now that is challenging! • Try this one: 36 – 30. • How did you know the answer so
fast? • Yes! Is it easier to subtract just tens!
Concept Development Continued• Now, can you tell me how
34 – 28 and my other problem, 36 – 30, are related? Turn and talk. • Now how long is each bar? • We added 2 to each bar to
make the problem easy! • Now it’s your turn. On your
white board, solve these problems by making a tape diagram. Add on to both numbers to make the problem easier.
22-8
26-19
33-18
Concept Development Continued• There are 6 red cubes on one end
and 4 red on the other end. How many yellows are in the middle?
• What is the total number of cubes? • Let’s make 2 different addition
sentences. What is the addition sentence for the total number of cubes?
• Now instead let’s join the 1 yellow with the 6 red.
• How do you know this is true
6+5 = 7+4?
Concept Development Continued• Let’s use that same idea with
larger numbers to make tens. • Let’s solve 28 + 36. • What does 28 need to be the next
ten? • What is 2 less than 36? • How do you know this is true:
28+36=30+34? • We can also show 2 more for 28
with our number bond. • Let’s write both models in our
journals and explain them to your partner.
Concept Development Continued
•Let’s do some more practice with the following problems:
19+35
37+4678+24
36+29
Story Problem
•Carlos bought 61 t-shirts. He gave 29 of them to his friends. How many t-shirts does Carlos have left?
•Solve!•Share!