The second grade mathematics Huanggang secret volume 10 reference answer the first big question, the seventh small question and the third small question: count one.
It is really one to ten. First of all, our writing hand is the right hand. Look, the single digits are on the right, right? Son, think about it. If I count tens of digits first, if I need to borrow single digits or borrow them for a period of time, do I have to count them again in ten digits? Is that an extra step? For example:+18 In this formula, if you first calculate the ten digits, you get 5+ 1=6, and then calculate the one digit-74, you get 6+8 = 65438. The correct way is to calculate the unit number first and get 6+8= 14, so the unit number is 4,5+1+1= 7 (the second1is the unit number), and the ten digits are 7. You can ask questions if you don't understand.