Equations and Unknowns
Solve 2,392 + x =5,003
2,611
Evaluate (40+90)×2.
260
You buy 7 light bulbs at $2 each. You pay with $20. How much change do you get?
$6 change
Round $28.95 to the nearest ten.
$30
A jacket costs $47.80 and a pair of gloves costs $12.40. You buy one jacket and two pairs of gloves. What is the estimated total cost using rounded numbers?
$50 + (2 × $12) = $74
If x+1,250=2,000, what is x?
750
Solve (50−10)+(5−3).
42
Which expression matches the problem: You buy 7 light bulbs at $2 each. You pay with $20. How much change do you get?
7×2−20
(20−2)×7
20−7×2
7×20−2
20−7×2
Round $14.25 to the nearest ten.
$10
A book costs $18.75 and a notebook costs $6.20. You buy three notebooks and one book. What is the estimated total cost using rounded numbers?
$20 + (3 × $6) = $38
Write an equation for: “A number plus 500 equals 1,000.”
x+500=1,000
Calculate 50+10×4−20.
70
Write your own word problem that matches the equation x−15=45.
“Sally had some money. After spending $15, Sally had $45 left.”
Estimate the total cost of a helmet ($28.95) and two flashlights ($14.25 each).
$30 + (2 × $10) = $50
A bicycle helmet costs $28.95 and each flashlight costs $14.25. You buy two flashlights and one helmet. What is the estimated total cost using rounded numbers?
$30 + (2 × $10) = $50
Solve x−345=1,000
x=1,345
Simplify: 100 - (25 x 2) + 10.
60
A store sells apples for $3 each. If you buy 5 apples, how much do you spend?
$15
Round 2,392 to the nearest hundred.
2,400
A garden is 12 m long and 8 m wide. What is its perimeter?
2×(12+8)=40
If 3x=1,200, what is x? (hint: you divide 1,200 by 3)
x=400
Compute (12+8)×(5−2).
60
A bus has 40 seats. If 28 are filled, how many are empty?
12
Estimate the sum: 4,876 + 3,214 by rounding to the nearest thousand.
5,000 + 3,000 = 8,000
A computer program was discounted by $48 and now costs $67. What was the original price?
$67 + $48=$115