Show:
Addition Properties and Patterns
Rounding

Estimating Sums and Differences
Relating Addition and Subtraction
Problem Solving

100

Fill in the missing number: ? + 90 = 90

0

100

What number is halfway between 200 and 300?

250

100

Round to the nearest ten to estimate: 9 + 27

40

100

Solve 128 - 19 using mental math. 

109

100

Free point: What’s tomorrow? 

Fabulous Friday!!

200

Identify the property: 17 + 0 = 17

Identity (zero) Property

200

Round to the nearest ten: 531

530

200

Round to the nearest ten to estimate: 138 + 435

580

200

Solve 236 + 243 using mental math. 

479

200

Bethany’s bakery makes 204 scones in January. Her bakery made 24 fewer scones in February. How many pies did her baker make in both months? WHAT IS THE HIDDEN QUESTION?

Figure out how many scones she made in February: 204 - 24 = 180 scones. 

300

Identify the property: 42 + 23 = 23 + 42

Commutative Property

300

Round to the nearest hundred: 428

400

300

Round to the nearest hundred to estimate: 103 + 179

300

300

Solve 252 + 44 using mental math. 

296

300

Bethany’s bakery makes 204 scones in January. Her bakery made 24 fewer scones in February. How many pies did her baker make in both months?

204 + 180 = 284 scones

400

Is the sum of two odd numbers odd or even? Explain why. 

Even

400

Round to the nearest ten: 855

860

400

Round to the nearest hundred to estimate: 462 + 251

800

400

How does knowing 557 - 232 = 325 help you solve 325 + ? = 557?

You can use it to solve the bottom equation using inverse operations. 
400

Kady’s office building has 16 shelves. Morgan’s bank has 98 shelves. Nate’s bank has 43 shelves. How many more windows do the banks have than the office building? WHAT IS THE HIDDEN QUESTION?

98 + 43 = 141

Add the bank shelves together

500

Ralph says he can rewrite (4+5) + 21 as 9 + 21. Do you agree? Why or why not? 

Yes, this is known as the associative property. 

500

Round to the nearest hundred: 750

800

500

Jen has $236 and Dan has $289. Do Jen and Dan have more than $600 in all? Estimate to solve.

No

500

Mrs. Musser’s book has 634 pages. So far she has read 379 pages. How many more pages does Mrs. Musser need to read to finish her book? 

255 pages

500

Kady’s office building has 16 shelves. Morgan’s bank has 98 shelves. Nate’s bank has 43 shelves. How many more windows do the banks have than the office building?

125

Bank shelves - office shelves