# Add and Subtract Multiples of 100

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Add and Subtract Multiples of 100
Lesson 5.2:

Place Value Show 1 hundred, 4 tens, and 2 ones in chips on a place value chart. Write the number below it. Say the number in unit form. 1 hundred 4 tens 2 ones Say the number in unit form using only tens and ones. 14 tens 2 ones

Place Value Say the number in unit form using only hundreds and ones.
1 hundred 42 ones Say the number in standard form. 142 Add 2 hundreds to your chart. How many hundreds do you have now? 3 hundreds

Place Value What is 200 more than 142? 342
Add 3 hundreds to 342. How many hundreds do you have now? 6 hundreds What is 300 more than 342? 642

Place Value Now subtract 4 hundreds from 642. What is 400 less than 642? 242

How Many More Hundreds? If I say 300 – 200, you say 100.
To say it in a sentence, you say, “100 more than 200 is 300.” Ready? 300 – 200 100 Say it in a sentence. 100 more than 200 is 300.

How Many More Hundreds? Say each answer in a sentence that tells how many more: 405 – 305 801 – 601 650 – 350 825 – 125 999 – 299

Application Problem Max has 42 marbles in his marble bag after he added 20 marbles at noon. How many marbles did he have before noon? Solution

Concept Development Problem 1
Use your place value chart and base ten blocks. Yesterday we added and subtracted 1 hundred. Today, let’s add 2 hundreds, then 3 hundreds, and more! How many do you see? Say the number in unit form. 1 hundred 2 tens 5 ones Show me this number with your base ten blocks. How much do you see now? 325

Concept Development Problem 1
How can you show this change using your base ten blocks? Add 2 more hundreds Show that on your chart. Now I am going to add 2 more hundreds. You do it too. Turn and talk, what will happen to the number when I add 2 hundreds? The number in the hundreds place will get bigger by 2. The ones and tens digits will stay the same.

Concept Development Problem 1
Add 2 more hundreds. What is ? Say it in unit form. 5 hundreds, 2 tens, 5 ones!

Concept Development Problem 1
If I asked you to add 3 hundreds to 450, how could you solve that? Count on by a hundred 3 times. Change the 4 to 7 because 4 hundreds plus 3 hundreds is 7 hundreds. Let’s show that on the board using both simplifying strategies, the arrow way and number bonds. I know many of you can just do mental math!

Concept Development Problem 1
I can add 3 hundreds using the arrow way, as we did yesterday. I can also break apart the hundreds and tens with a number bond, add the hundreds, and then add the tens. No matter which way I write it, when I add hundreds to a number, the tens and ones stay the same!

Concept Development Problem 1
Now it’s your turn. In your notebook, solve Show me your board when you have an answer. = 300 = 347 + 200

Concept Development Problem 1
Try these:

Concept Development Problem 2
Now, let’s subtract 2 hundreds, then 3 hundreds, and more! How many do you see? 725 Say it in unit form. 7 hundreds 2 tens 5 ones 5 hundreds 2 tens 5 ones

Concept Development Problem 2
I am going to subtract 2 more hundreds. Turn and talk: What will happen to the number when I subtract 2 hundreds? The number in the hundreds place will get smaller by 2. The number will get smaller by 200. It will be 325 because 5 hundreds minus 2 hundreds equals 3 hundreds. The other digits stay the same. What is 525 ─ 200?

Concept Development Problem 2
What is 525 ─ 200? 325 Say it in unit form. 3 hundreds 2 tens 5 ones Let’s subtract 3 hundreds from 582. Take a moment and work on your place value chart to solve 582 – 300.

Concept Development Problem 2
We have an extra simplifying strategy when we are subtracting. We can count up from the part we know. What is the whole? 582 What is the part we know? 300

Concept Development Problem 2
How can we show the missing part with an addition problem? We can use the arrow way, counting first by either tens or ones. Try it with a partner. Starting at 300 you can add 2 hundreds first and then 82, or add 82 first and then add 2 hundreds.

Concept Development Problem 2
Let’s try again: 620 – 400 541 – 200 797 – 300

Practice Problems 1. Solve using place value strategies. Use the arrow way or mental math and record your answers. You may use scratch paper if you like. a. 2 hundreds 4 tens + 3 hundreds = __ hundreds __ tens = _____ b = ___ = ___ = ___ c = ___ = __ = ___

Practice Problems 2. Solve using place value strategies. Use the arrow way or mental math and record your answers. You may use scratch paper if you like. 6 hundreds 2 ones - 4 hundreds = ____ hundreds ____ tens ____ ones a = ___ = ___ ___ = 350 b = ___ = ___ = ___ c ___= ___= ___ = 68

Practice Problems 3. Fill in the blank to make true number sentences. Use place value strategies, number bonds, or the arrow way to solve. a. 200 more than 389 is ___________. b. 300 more than ___________ is 568. c. 400 less than 867 is __________. d. __________ less than 962 is 262.

Practice Problems 4. Jessica’s lemon tree has 526 lemons. She gave away 300 lemons. How many does she have left? Use the arrow way to solve.

Exit Ticket Solve using place value strategies. Use the arrow way or mental math and record your answers. You may use scratch paper if you like. = __ = __ __ = 590 = __ __ = __= 136