value of the sum
find the difference
rounding
write an equation
solve it
100
456+321=
777
100
347-124=
223
100
What is 238 rounded to the nearest tens?
240
100
There are 50 pieces of candy in the jar. 20 pieces were jolly ranchers. 10 were starburst. The rest of the pieces were reeces.
reeces= r
50-(10+20)=r
20+10+r=50
100
A classroom has 30 desks. There are 15 students who show up up and then 12 more students show up to class. How many empty seats are there?
3 empty seats
200
539+232=
771
200
468-248=
220
200
What is 485 rounded to the nearest hundreds?
500
200
A box has 150 pencils. Three students take six pencils each. How many pencils are left?
*use a letter to represent the unknown quantity
150-(3x6)= p
200
A theater has 250 seats. They've sold 185 tickets so far. How many tickets are still available?
65 tickets
300
198+785=
983
300
567-193=
374
300
What is 750 rounded to the nearest tens and nearest hundreds?
nearest tens: 750
nearest hundreds: 800
300
A box contains 70 markers. 4 students each take 2 markers. Letter m represents how many markers are left in the box.
70 - (4x2) = m
70 - (2x4) = m
300
Explain or show why this happens. Why is there a diagonal line?
The sums are the same because they all have numbers which added up to the sum. For example 4+1 or 1+4=5, and 2+3 or 3+2=5.
400
978+549=
1,527
400
550-253=
297
400
What is 245 rounded to the nearest tens and nearest hundred?
nearest tens: 250
400
There are 98 pencils in a bag. There are 5 students who each take 7 pencils from the bag. The number of pencils left in the bag is p.
98-(5x7)=p
400
There are seats for 400 students in the auditorium. There are 121 students from Anthony's school and 180 students from Jaylah's school at the performance.
Jaylah estimates that there will be about 100 empty seats. Do you agree with Jaylah? explain or show your reasoning.
I agree with Jaylah because if we add 121+180= 301 students.
400-301=99 which is close to Jaylah's estimate of 100
500
356+768=
1,124
500
900-427=
473
500
What is 304 rounded to the nearest tens and nearest hundreds?
nearest tens: 300
nearest hundreds: 300
500
A bag has 60 crayons. 4 students each take 5 crayons. Then, the teacher adds 12 more crayons. How many crayons are in the bag now?
60 - (4x5) + 12 = c
500
There are seats for 800 students in the auditorium. There are 234 students from Madeline's school and 356 students from Sofie's school at the performance.
Sofie estimates that there will be about 100 empty seats. Do you agree with Sofie? explain or show your reasoning.
I disagree with Sofie because when you add the amount of students together 234+356= 590. Then, if we subtract 800-590=210 which is a lot more than the estimated 100 empty seats Sofie said.