Addition
What is 243 + 178?
421
What is 642 − 258?
384
Estimate: 48 + 27
About 80
What time is 3 hours after 9:00 AM?
12:00 PM
What is the answer to an addition problem called?
Sum
What is 586 + 437?
1,023
What is 900 − 476?
424
Estimate: 163 + 289
About 450
What time is 45 minutes before 2:30 PM?
1:45 PM
What is the answer to a subtraction problem called?
Difference
What is 729 + 865?
1,594
What is 1,204 − 689?
515
Estimate: 2,384 − 1,167
About 1,200
How many minutes are there in 2 hours and 15 minutes?
135 minutes
What is it called when you round numbers to find a quick, close answer?
Estimation
What is 1,345 + 2,789?
4,134
What is 3,010 − 1,768?
1,242
Anna bought items costing $127, $246, and $318. About how much did she spend in total?
About $700
Jamal started reading at 4:10 PM and read for 1 hour and 25 minutes. What time did he finish?
5:35 PM
What do we call the amount of time between a start and end time?
Elapsed time
What is 3,298 + 4,876 + 2,157?
10,331
What is 6,432 − 2,987 − 845?
2,600
A school library had about 2,950 books. Over the year, about 1,470 were borrowed. About how many books are left?
About 1,500
The movie started at 6:45 PM and ended at 9:10 PM. How long was the movie?
2 hours and 25 minutes
What is the name for numbers that are easy to add, subtract, or estimate with (like 100, 50, or 10)?
Friendly Numbers