1/8 + 1/9 =?
1/28 + 1/56 =?
1/7 – 1/11 =?
1/31 – 1/62 =?
你能在 1 分鐘內心算以上各題的答案嗎?
這些算式有甚麼特點?兩個分母之間有甚麼關係?分子又怎樣?這些特點有助你心算嗎?
一起來挑戰「分數獵人」吧!
Can you calculate the above in just a minute, without any tools?
Is there anything special in these equations? What are the relationship between the denominators? How about the numerators? How would that help you?
Lets go F-hunting!