Fish in the sea
(1) Calculate, paying attention to the parentheses
| (40 + 10) + 10 = | (66 + 5) + 7 = | (88 + 9) + 7 = | 5 + (74 + 6) = |
| 7 + (35 + 20) = | 10 + (50 + 5) = | (39 + 20) + 10 = | 5 + (41 + 8) = |
(2) Calculate:
| 41 + = 61 | + 58 = 90 | 60 − = 24 | − 20 = 65 |
| 25 + = 82 | + 54 = 83 | 99 − = 32 | − 67 = 20 |
| 54 + = 95 | + 77 = 90 | 76 − = 33 | − 69 = 35 |
(3) Subtract and check by adding
| 93 − 40 = 53 | since 53 + 40 = 93 | 72 − 20 = | since + 20 = |
| 85 − 40 = | since + 40 = | 92 − 30 = | since + 30 = |
| 52 − 30 = | since + 30 = | 47 − 30 = | since + 30 = |
| 78 − 20 = | since + 20 = | 48 − 30 = | since + 30 = |
|
Captain John went fishing. First, he caught 20 colorful fish in his net. A little later, while sailing past a coral reef, he caught another 10 blue fish.
(a) How many fish did Captain John catch in total? After that, while returning to the harbor, several seagulls circled above the boat. One seagull grabbed 10 fish from the net.(b) How many fish remained in Captain John's net? Finally, when he arrived at the harbor, his friend Xavi gave him another 20 small, silver fish that he had caught himself.(c) How many fish does Captain John have in total now? (d) Additional question below the image (for those who want more) → |
 If Captain John decided to give half of all his fish to his cat named Sara, how many fish would Sara receive? |
Share exercise: