Question

1 . Alberto has 318 baseball cards and 273 basketball cards. Estimate how many sports cards Alberto has. Describe the strategy you used to estimate. 2. Alberto has 92 stamps in one large album and 38 stamps in another small album. How can he use mental math to find how many more stamps are in the large album? Use drawings to show your answer. 3. Alberto has 62 pennies, 41 nickels, and 29 dimes. What strategy can Alberto use to find the total number of coins? Describe it and show . 4. Suppose Alberto collects another 343 coins. How many coins will he have in his collection now? Describe two strategies you can use. then choose one strategy and solve. 5. Of Alberto's total number of coins, 168 are quarters. Describe two strategies you can use to find how many coins are not quarters. Estimate the difference. Then choose one strategy and solve.

Answer 1

For 1. To estimate how many sports cards Alberto had, you would round each number to the nearest ten, so 318 would become 320. 273 would then become 270. You would then add those two and would get 590. So, Alberto had 590 sports cards (estimated). If you were looking for the actual answer (not estimated) , you would get 591.