14 + ▲ = 31
What is the value of ▲?
14 + ▲ = 31
▲ = 31 - 14
▲ = 17
Use estimation to the closest tens to solve this equation.
85 + 35 = ?
Result around:
90 + 40 = 130
Use estimation to the closest tens to solve this equation.
556 – 49 = ?
Result around:
560 – 50 = 510
At the beginning of January, Tom had 120 marbles. At the beginning of February, he had 200. How many marbles does he collect in January?
Write the equation using symbols for the number of marbles Tom collected.
Bonus 5 points: Solve your equation.
▲ = the number of marbles Tom collected
Equation:
120 + ▲ = 200 marbles
or
▲ = 200 − 120 marbles
Bonus answer: ▲ = 80 marbles
A library received 45 books from one school and 23 books from another school.
How many books did the library receive in total? Use estimation to the nearest tens.
45 + 23 = ?
With estimation:
50 + 20 = 70
▲ − 47 = 43
What is the value of ▲?
▲ − 47 = 43
▲ = 43 + 47
▲ = 90
Use estimation to the closest hundreds to solve this equation.
863 – 112 = ?
Result around:
900 – 100 = 800
Use estimation to the closest hundreds to solve this equation.
4069 – 607 = ?
Result around:
4100 – 600 = 3500
Amia prepares her juice stand to sell her litres of juice. Throughout the day, she sells 310 litres of juice. When it is closing time, Amia only has 450 litres of juice left. How many litres of juice did Amia have originally?
Write the equation using symbols for the litre of juice Amia had originally.
Bonus 5 points: Solve your equation.
▲ = the litre of juice Amia had originally
Equations:
▲ − 310 = 450 litres of juice
or
▲ = 450 + 310 litres of juice
Bonus answer: ▲ = 760 litres of juice
P5 ordered 275 pencils, 186 erasers, and 215 sharpeners.
How many items did P5 order altogether? Use estimation to the nearest tens.
275 + 186 + 215 = ?
With estimation:
280 + 190 + 220 = 690
21 - ◎ = 16
11 - ◎ + ▲ = 8
76 - ▲ = ?
21 - ◎ = 16
◎ = 21 - 16
◎ = 5
11 - ◎ + ▲ = 8
11 - 5 + ▲ = 8
6 + ▲ = 8
▲ = 8 - 6
▲ = 2
76 - ▲ = 76 - 2 = 74
Use estimation to the closest hundreds to solve this equation.
671 + 210 – 182 = ?
Result around:
700 + 200 – 200 = 700
Use estimation to the closest hundreds to solve this equation.
3481 – 618 – 1367 = ?
Result around:
3500 – 600 – 1400 = 1500
Tamar is a card and keychain collector. Originally, she had 3 cards and 7 keychains. Today, she buys 2 card packs and 1 keychain box. Now, she has 25 cards and 12 keychains.
Write the equation using symbols for the number of cards per pack and keychains per box.
Bonus 5 points: Find the total of cards in one pack + keychains in one box
◎ = number or card per pack
▲ = number of keychain per box
Equations:
3 + ◎ + ◎ = 25
7 + ▲ = 12
Bonus answer:
◎ = 11
▲ = 4
◎ + ▲ = 11 + 4 = 15
A fruit truck carried 580 kg of apples and 760 kg of oranges to the market.
After selling 120 kg of fruits in total, how many kilograms of fruits were left on the truck? Use estimation to the nearest hundred.
580 + 760 - 120 = ?
With estimation:
600 + 800 - 100 = 1300
◎ + ◎ + ◎ = 39
◎ - ▲ – 5 = 2
◎ - ▲ = ?
◎ + ◎ + ◎ = 39
◎ = 39 : 3
◎ = 13
◎ - ▲ – 5 = 2
13 - ▲ – 5 = 2
8 - ▲ = 2
▲ = 8 - 2
▲ = 6
◎ - ▲ = 13 - 6 = 7
Use estimation to the closest thousands to solve this equation.
8853 – 2923 – 3360 = ?
Result around:
9000 – 3000 – 3000 = 3000
Use estimation to the closest hundreds to solve this equation.
6022 – 2615 + 9924 = ?
Result around:
6000 – 2600 + 9900 = 13300
Rahma goes to buy some school supplies. If she buys 4 books with $50, she will get $6 for change. If she buys 1 book and 1 pencil case with $50, she will get $26 in change.
Write the equation using symbols for the price of one book and one pencil case.
Bonus 5 points: If Emma wants to buy 2 books and 2 pencil cases, how much does she need to pay?
◎ = price of 1 book
▲ = price of 1 pencil case
Equations:
50 - ◎ - ◎ - ◎ - ◎ = 6
50 - ◎ – ▲ = 26
Bonus answer:
◎ = $11
▲ = $13
◎ + ◎ + ▲ + ▲ = 11 + 11 + 13 + 13 = $48
During a charity event, students collected $6375 on Day 1, $4620 on Day 2, and $3955 on Day 3. They used $8150 to buy school equipment.
How much money did they have left after the purchase? Use estimation to the nearest hundred.
6375 + 4620 + 3955 - 8150 = ?
With estimation:
6400 + 4600 + 4000 - 8200 = 6800
38 - ◎ - ◎ = 12
5 + ◎ + ▲ = 29
◎ - ▲ = ?
38 - ◎ - ◎ = 12
- ◎ - ◎ = 38 - 12
- ◎ - ◎ = 26
◎ = 26 : 2
◎ = 13
5 + ◎ + ▲ = 29
5 + 13 + ▲ = 29
18 + ▲ = 29
▲ = 29 - 18
▲ = 11
◎ - ▲ = 13 - 11 = 2
Use estimation to the closest thousands to solve this equation.
8289 + 5487 + 5691 = ?
Result around:
8000 + 5000 + 6000 = 19000
Use estimation to the closest thousands to solve this equation.
7603 + 24396 – 9631 = ?
Result around:
8000 + 24000 – 10000 = 22000
Emma and Yuki go to a cafe to buy ice cream and waffles. Emma buys 2 waffles and needs to pay $28. Yuki buys 1 ice cream with $30, and the change is equal to 1 waffle.
Write the equation using symbols for the price of one waffle and ice cream.
Bonus 5 points: If Emma wants to buy 1 ice cream and 1 waffle, how much does she need to pay?
◎ = price of 1 waffle
▲ = price of 1 ice cream
Equation:
◎ + ◎ = 28
30 - ▲ = ◎
Bonus answer:
◎ = $14
▲ = $16
▲ + ◎ = 16 + 14 = $30
A construction company planned to use some material for a building project: 9480 kg of cement, 7265 kg of sand, and 6890 kg of gravel.
However, by the end of the week, they had already used 15,700 kg of the materials.
How many kilograms of materials were still unused? Use estimation to the nearest thousand.
9480 + 7265 + 6890 - 15700 = ?
With estimation:
9000 + 7000 + 7000 - 16000 = 7000