Guess and Check
Lesson
Topic Index | Grade 4 Math | Elementary Test Prep | StudyZone

The Guess and Check strategy requires students to guess a solution, test its correctness, and refine the guess using logical reasoning.

If you don't know how to solve a problem, make an educated guess at the answer. Check your guess. If you're wrong, use what you've learned in checking your guess to make a better guess. Continue to guess, check, and modify until you find the answer.
 

Example

Read Students in Mrs. Carroll's sixth-grade class ordered school shorts. The denim shorts cost $15 and the flannel shorts cost$9. If Mrs. Carroll's students ordered 28 shorts and spend a total of $300, how many denim shorts did they order?
Plan One way to solve the problem is to make a guess, test it, and revise your guess until you find the correct answer.
Solve Guess: 10 for $15, and 18 for $9
Test: 10 x $15 = $150 and 18 x $9 = $162
$150 + $162 = $312

Revise: Too high. Try fewer $15 shorts.

Guess: 9 for $15, and 19 for $9
Test: 9 x $15 = $135 and 19 x $9 = $171
$135 + $171 = 406

Revise: Too high. Try fewer $15 shorts.

Guess: 8 for $15, and 20 for $9
Test: 8 x $15 = $120 and 20 x $9 = $180
$120 + $180 = $300

The students ordered 8 denim shorts.

 

Remember: How can you use each guess to help you decide on a better next guess?

If the amount is too high, try fewer. If too low, try more.
 

Let's Practice!
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Topic Index  | Grade 4 Math | Elementary Test Prep | StudyZone

Created by Carol Carroll
Updated by Nicole Freebern
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