My mother gave me 100 yuan to buy school supplies on Sunday. I happily took the money to the supermarket and bought an eraser 2 yuan, a schoolbag 32 yuan, a pencil box 5 yuan, a crayon 12 yuan and a bundle of pencils 10 yuan. The cashier asked me to calculate how much it would cost. I remember the calculation method of continuous subtraction in school math class. The formula is: 100 yuan -2 yuan -32 yuan -5 yuan-12 yuan-10 yuan =6 1 yuan. The cashier praised me as a good boy who loves to study, and I smiled happily.

Math diary, Grade One, Grade Two, 200 words.

Today, we learned about RMB. 1 yuan has 10 1 angle, and 1 yuan has two 50 angles. 10 yuan contains 10 0 yuan, 10 yuan contains 2 5 yuan, 10 yuan contains 5 2 yuan, 100 yuan contains 2 50 yuan, 10 yuan contains 10. Renminbi is divided into two denominations: paper money and coins. We should cherish RMB, don't scribble on it, scrimp and save at ordinary times, study hard and make progress every day.

Math diary, Grade One and Grade Three, 200 words.

Today, I finished my homework early in the morning. My mother saw it and came up to me and said, "Zini, play a game with you!" " ""good! " I readily agreed. Mother brought a round cardboard and fixed a movable pointer in the center of the cardboard with a nail. The cardboard is divided into 24 grids on average, and the number 1-24 is written in each grid. "Mom, what are the rules of the game? Say it! "I said impatiently that the rules of the game are simple, that is, the next number must be added to the pointer pointing to the odd or even number; If it adds up to an odd number, I win; If the total is even, you win. "Mom said with a smile.

I saw that the rules of the game were very simple. I played for more than a dozen times in a row, but I couldn't beat my mother every time. My mother smiled. "Why is it always singular?" I asked my mother puzzled. Mom said, "Think for yourself!" So, I racked my brains and finally remembered a formula that the teacher once said: odd+even = odd. Now I can understand that if the pointer is singular, then the next number must be even; If the pointer points to an even cell, then the next added number is odd, so no matter which cell the pointer points to, the added number is odd; Mom won with this rule.

In the world of mathematics, there are many wonderful laws. As long as we learn math well and make good use of it, it is everywhere!

Math diary, Grade Four, Grade One, 200 words.

Today is the Dragon Boat Festival. My mother bought dumpling wrappers, and our family happily wrapped jiaozi. I got 15, my dad got 2 1, and my mom got 30. My father said he would test my math study. The question is: How many jiaozi? 15+2 1+30=66 (pieces). Jiaozi is ready, I ate 10, my father ate 25, my mother ate 5, and my mother said, how many are left? 66- 10-25-5=26 (a) My parents smiled happily and praised me for learning math well.

Math diary, Grade Five, Grade One, 200 words.

Today, when I was doing my homework for the math interest group, I was stumped by a math problem: "A pile of watermelons, half and half, less than half, how many watermelons are there in this pile?" This topic is to count the number of watermelons, but it has no figures, so many "half" can confuse me. I was so anxious that I shouted at my sister, "How to calculate this problem?" My sister stared at it for a while and said with a smile, "If you think about it carefully, you can draw a picture."

So, I suppose there are eight watermelons, and I draw eight watermelons on the paper. Therefore, one half (1) is less than the other half (2) 1. I think this is wrong. Later, when my eyes lit up, I took off half a watermelon, that is, four watermelons and a picture. "Half of the four watermelons are half watermelons, isn't it half less than half of this watermelon (1)?" I jumped for joy! "Ha ha! I calculated that there are four watermelons in this pile! "

Math diary, Grade One of Liutiao Primary School, 200 words.

Today, the teacher taught us the jigsaw puzzle, which consists of a parallelogram, a square and five triangles. In our daily life, we can't do without the basic plane graphics in the puzzle, which can spell out interesting graphics, such as trees, houses, little girls, kittens and so on. As long as we study hard and love to operate, puzzles can be useful and interesting.