Show:
Addition & Subtraction Meanings
Using Mental Math to Add & Subtract
Rounding
Estimating Sums & Differences
Reasonableness
100

What is an addend?

The numbers being added together.
100

How can you use the breaking apart method to break apart the number 36. 

30+6

100

Round this number to the nearest ten: 61

60

100

If both addends are rounded up, will the estimate be greater than or less than the actual sum?

Greater than the actual sum. 

100

Think about how many students are in this school. What is a REASONABLE answer?

400-800

200

What property of addition is being shown here?

19+0=19

Identity (Zero) Property of Addition

200

Use the breaking apart method to write this number: 78

70+8

200

Round this number to the nearest hundred: 251

300

200

Round to the nearest tens to estimate the sum: 

28+46

30+50=80

200
Think about how many students are in this school. What is NOT a reasonable answer?

1 student, 10 students, 1,000,000 students, etc. 

300

What is the missing number?

__+8=8+2

2

300

Use breaking apart to add 25+12. Show me how you broke the numbers apart on your answer. 

10+2=12

20+5=25

20+10=30

2+5=7

30+7=37

300

Round this number to the nearest thousand: 8,993

9,000

300

Round to the nearest hundred to estimate the sum: 

114+58

100+100=200

300

Carl practices piano 45 minutes each day. Today, he practiced 15 minutes after school and 10 minutes before dinner. How much time does he still need to practice?

A: 70 minutes 

B: 60 minutes 

C: 35 minutes

D: 20 minutes

D: 20 minutes

400

The Jet Propulsion Lab had 9 missions between 2003 and 2006. Two of these missions were to study comets. How many of these missions did not study comets?

7 missions

400

Find the difference using mental math or an algorithm:

29-18

11

400

Round this number to the nearest ten: 342

340

400

Round to the nearest ten to estimate the difference:

579-214

580-210=370

400

Carrie has 15 pennies. Her brother has 10 more pennies than Carrie. How many pennies do they have in all?

A: 40 pennies

B: 25 pennies

C: 10 pennies

D: 5 pennies

A: 40 pennies

500

Show me an example of the associative property of addition. 

(a+b)+c=a+(b+c)

500

Find the difference using mental math or an algorithm:

97-14

83

500

Round this number to the nearest hundred: 2,572

2,600

500

Round to the nearest hundred to estimate the difference:

704-369

700-400=300

500

Henry is reading a book that is 85 pages long. HE read 35 pages yesterday and 24 pages today. How many pages did James read in the two days?

35+24=59 pages