章魚艦長小八的太空船要轉向去探索星球。第 1 關要自己把量角器拖到角的頂點、轉到 0° 線對準一條邊，再讀出角度（會出現讀錯內外圈的陷阱）；第 2 關照指令拖雷達光束，畫出指定度數的航線再發射；第 3 關把太空船順時針轉 1/4 圈、半圈、3/4 圈，再算出兩次轉向一共幾度、還差幾度轉滿一圈、幾個直角是幾度。
適合年級：四年級（約 9～10 歲）。對應 108 課綱（十二年國教）數學單元：四年級「角度、量角器和旋轉角」。各版本教科書的單元順序不同，完整對照請看國小數學課綱對照表。免費、無廣告、不用註冊，手機、平板、電腦打開就能玩，題目有注音，也會念出來。
陪玩小提醒：量角時最常讀錯內外兩圈刻度。可以先問孩子「這個角比直角大還是小？」，再決定讀到的度數合不合理。
Captain Octo’s spaceship has to turn towards new planets. In level 1 children drag a protractor onto the vertex, turn it so the 0° line lies on one arm and read the angle (with the inner/outer scale trap); in level 2 they drag the radar beam to draw a given angle and launch; in level 3 they turn the ship clockwise by quarter, half and three-quarter turns and work out total turns, what is left of a full turn, and right angles in degrees.
Suits Grade 4 (about age 9–10) in Taiwan. Taiwan curriculum (12-year basic education) unit: Degrees, protractors and turns (Grade 4). Free with no ads and no sign-up, in Traditional Chinese with zhuyin and in English, read aloud. See the Taiwan elementary maths curriculum map.