Mathematical content Flashcards
Percentages
Percentage means divide by 100
Percentage to a decimal
- Remove the % sign
- Move the decimal point two places to the left
Decimal places
Number of digits right to the decimal point.
Example 0.0045 is 4 decimal places.
Decimal to a fraction
- Work out the number of decimal places in your number.
- If there are two decimal places then the denominator is 100, three decimal places then the denominator is 1000 etc.
- Reduce the fraction by finding the highest common factor: the biggest number that divides evenly into both parts of the fraction.
Ratios
Expressed as part-to-part or part-to-whole ratios.
Should always be divided by the highest common factor.
Significant figures
A way to simplify very large or very small numbers by replacing some digits with a zero.
Standard form
Another way of expressing very large or very small numbers. The rule is (number between 1 and 10) x 10
Estimates and order of magnitude
Estimates - give a number to just 1 or 2 significant figures.
Order of magnitude - calculate standard form and compare exponents.
Substituting values
You are given the equation a=b+c
You are given values for b and c (b=4 and c=7)
What is a? (a=11)