Marcus is making groups of 2 with his 10 toy cars. He wants to make sure each group has exactly 2 cars and no cars are left over. What tool approach would help him check this best?
- Line up all his cars in one long row from big to small
- Count all his cars one more time to make sure he has 10
- Put 2 cars together, then 2 more, then 2 more, and keep going (correct answer)
- Pick out his 2 favorite cars and put them in the first group
Explanation: When you need to make equal groups with no leftovers, the best strategy is to actually form the groups and see if it works out evenly. Answer C is correct because it shows the right approach: systematically putting 2 cars together, then 2 more, then 2 more, and continuing this pattern. This method lets Marcus physically create the groups he wants and see if all 10 cars can be divided evenly into groups of 2. By the end, he'll have made 5 groups with exactly 2 cars each, proving that 10 can be divided by 2 with no remainder. Answer A is wrong because lining up cars by size doesn't help with grouping - it just organizes them by a different attribute. Answer B misses the point entirely; Marcus already knows he has 10 cars, but counting again doesn't tell him whether 10 can be split into equal groups of 2. Answer D focuses on choosing favorite cars, but this doesn't help determine if all the cars can be evenly grouped - it only deals with one group. The key insight is that when you're checking if items can be divided into equal groups, you need to actually try making those groups. Simply counting or organizing by other qualities won't answer the grouping question. Remember: When a math problem asks about making equal groups, always look for the answer choice that involves actually forming those groups step by step. This hands-on approach is the most reliable way to check if equal grouping is possible.