1, number of copies × number of copies = total.

Total copies/copies = copies.

Total copies/copies = copies.

2. Unit price × quantity = total price.

Total price/unit price = quantity.

Total price ÷ quantity = unit price.

3. Speed × time = distance.

Distance/speed = time.

Distance/time = speed.

4. Work efficiency × working time = total workload.

Total amount of work ÷ efficiency = working hours.

Total amount of work ÷ working time = working efficiency.

5. Appendix+Appendix = sum.

And-one addend = another addend.

6. Minus-Minus = difference.

Negative difference = negative.

Difference+subtraction = subtraction.

7. Factor × factor = product.

Product-one factor = another factor.

The knowledge points of the second volume of mathematics in the sixth grade of primary school must be memorized;

Negative numbers must be remembered:

1, 0 is neither positive nor negative. It is the dividing line between positive and negative numbers. 0 is greater than all negative numbers and less than all positive numbers. Negative numbers are relatively large, regardless of the negative sign, and the numbers with large numbers are relatively small.

2. "+"can be omitted and "-"cannot be omitted.

3. Elements of the number axis: positive direction (indicated by arrow), origin (0 scale) and unit length (scale). The numbers on the left of 0 are all negative, and the numbers on the right of 0 are all positive.

Percent knowledge points:

1. discount: what percentage of the original price is sold? This is called discount. A few percent discount is a few tenths, that is, dozens of percent. For example, a 20% discount is 8/10, which is 80% of the original price.

2. Percentage: "A few percent" means a few tenths, that is, dozens of percent, and 35 percent means 3.5 percent, that is, 35 percent.

3. Taxable amount = total income × tax rate, tax rate = taxable amount/total income, total income = taxable amount/tax rate.

4. Interest = principal × interest rate× deposit period.

5. If 50 yuan is deducted from 100, that is, the whole hundred yuan is taken from the total price, and 50 yuan is deducted from every 100, and the part less than 100 is not preferential.

Formulas for circles, cylinders and cylinders:

1, in the same circle or equal circle, the diameter is twice as long as the radius, and the formula d = 2r is half as long as the diameter, and the formula r = d ÷ 2.

2. Find the circumference of a known diameter: circumference = pi × diameter, formula C=πd, diameter = circumference ÷ pi, formula d=C÷π.

3. Find the circumference with known radius: circumference =2× pi× radius, formula C=2πr, radius = circumference ÷2 times pi, formula r=C÷2π.

4. Find the area of the known radius: the area of the circle = pi × the square of the radius, and the formula S circle =πr2.

5. Find the area of the known diameter: the area of the circle = pi × (diameter ÷2) square, and the formula S circle =π(d÷2)2.

6. lateral area of cylinder = perimeter of bottom × height, formula S-side = perimeter of bottom surface of CH cylinder = side area ÷ height, formula C=s-side ÷ h; The height of the cylinder = the perimeter of the side area ÷ the bottom surface, and the formula h=S side ÷ C.

7. Surface area of cylinder = side area +2× bottom area, formula? S table = S side +2S bottom.

8. The volume of the cylinder is equal to the bottom area multiplied by the height, and the formula V cylinder =Sh, the height of the cylinder divided by the bottom area, and the formula H = V÷s；; The bottom area of a cylinder is equal to the volume divided by the height, and the formula s = v÷h

9. The volume of a cone is equal to one third of the volume of a cylinder with the same height as its bottom surface. The formula of cone volume is V= 1 /3Sh. The height of the cone is three times the volume divided by the bottom area, and the formula H = 3v÷s；; The area of the bottom of the cone is equal to 3 times the volume divided by the height, and the formula is s = 3v÷h.

10, ring area = large circle area-small circle area, and s ring = π r-π r.

1 1. Between a cone and a cylinder with equal volume and height, the bottom area of the cone is three times that of the cylinder, that is, the bottom area of the cone = the bottom area of the cylinder ×3, and the bottom area of the cylinder = the bottom area of the cone ÷3.