Which subtraction model-take-away, missing addend, comparison, or measurement-corresponds best to each problem below? (a) Elliot solved 17 problems and Todd solved 15 problems. How many more problems has Elliot solved than Todd? (b) On Maggie's 12 -mile hike to a lake, she came to a sign that said she had 4 miles left to reach the lake. How far has Maggie walked so far? (a) Which subtraction model corresponds best to this problem? Missing addend Measurement Comparison

For the first problem about Elliot and Todd, the best subtraction model would be **Comparison**. This model focuses on comparing two quantities to find out how much more one is than the other. Here, you’re finding how many more problems Elliot solved compared to Todd by subtracting Todd's score from Elliot's. As for the second problem involving Maggie's hike, the suitable model is **Measurement**. This model is used to determine the distance traveled or remaining, based on known intervals. By knowing the total distance of her hike and the remaining distance, you can calculate how far Maggie has walked thus far.