math Flashcards
(21 cards)
how to find a decimal
Divide the numerator by the denominator.
Add a decimal point and zeros if needed.
Keep dividing until the division stops or repeats.
how to find a percentage
Example: Find 25% of 80
50% of 80 = 40
Half of that (25%) = 20
✅ Answer: 25% of 80 = 20
✅ Example: Find 15% of 60
10% of 60 = 6
5% of 60 = 3
Add them: 6 + 3 = 9
✅ Answer: 15% of 60 = 9
🔹 2. Turn a fraction into a percentage (no calculator)
Step 1: Make the bottom (denominator) into 100 if you can.
how to do the mode
Mode = the number that appears most often in a list.
Back (Example):
List: 3, 7, 7, 2, 9
→ 7 appears twice.
✅ Mode = 7
how to do median
Median = the middle number when the numbers are in order.
(If there’s an even number of values, average the two middle ones.)
Back (Example):
List: 2, 4, 5, 8, 9
→ Already in order
→ Middle number = 5
✅ Median = 5
Another example (even amount):
List: 1, 3, 6, 10
→ Middle two: 3 and 6
→ (3 + 6) ÷ 2 = 4.5
✅ Median = 4.5
how to do mean
Mean = add all numbers, then divide by how many numbers there are.
Back (Example):
List: 2, 3, 5, 10
→ Add: 2 + 3 + 5 + 10 = 20
→ Divide by 4
✅ Mean = 5
f the average of 5 numbers is 10, then the total sum of those 5 numbers is:
5 times 10 =50
negative exponent
a ^ -n = 1/a^ n
hwo to divide fractions
For dividing fractions, keep the first fraction as it is, change the divide sign to a multiply and flip the second fraction upside down.
divide by decimals
turn into intergers
Prove algebraically that 0.73·
can be written as
11/15
numbers after decimal point have to match up
what do you do if you have a negative exponent
flip the fraction
after loook at notes
how to do compund interets without a calculator
e.g.10% of £3,000 =
10 percent of 3000 = 300
So after Year 1:
3000+300=3300
Year 2:
Now we take 10% of £3,300:330
So after Year 2:
3300
+
330
=
3630
3300+330=3630
how to figure out copound interest
initial x mutiplier (to the power of time)
how to figure out percentage profit
Profit percentage = (Profit/Cost Price) × 100.
how to divide something by something if hard
simplify it as a fraction
depreciation formula
initial value x rate to - poweredthe number of years
how do you do percentage increase / decrease
Percentage Change = ((New Value - Original Value) / Original Value) * 100.
what is one decimal place
0.1
space diagonal equation
Spacediagonal = cube root 3
face diagonal
square root
hwo to find upper bound of p
upperbound / lower bound
