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Flashcards in Number Deck (19)
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1
Q

What is a factor?

A

A number that divides exactly into another.

Eg 8 is a factor of 40.

2
Q

What do the letters L C M stand for?

A

lowest common multiple

3
Q

What is the most efficient method to find the HCF and LCMs of 148?

A

Break the number into its prime factors using a prime factor tree.

4
Q

What are the first six prime numbers?

A

2,3,5,7,11,13

5
Q

How do you convert a fraction to a decimal without a calculator?

A

Try to find an equivalent fraction where the denominator is a multiple of 10 or 100, because these values are easy to divide by.

6
Q

How do you convert a decimal to a percentage?

A

You need to multiply by 100.

7
Q

How do you convert a percentage to a fraction?

A

Write the percentage value over 100. If possible, cancel the fraction to its simplest form.

8
Q

What do the letters H C F stand for?

A

Highest common factor

9
Q

When do you need to find a common denominator?

A

When you add or subtract fractions.

10
Q

How do find a common denominator?

A

Look at denominators and if one is a multiple of the other, make the smaller value the same by multiplying. If both values are different, then find the LCMs of them.

11
Q

If I multiply a positive number by a negative one, what sign is my answer?

A

Negative.

Two signs are different when you multiply the answer is negative.

12
Q

If I square a negative number what happens?

A

The number is multiplied by itself and it becomes positive.

13
Q

Which is larger one ninth or one seventh?

A

One seventh because your amount is cut into seven equal pieces, not nine, so it must be larger.

14
Q

How do find the length of a square if you know it’s area is 36 cm^2

A

Square root 36

Because to get the area of a square you multiplied the length by itself.

15
Q

How do you round 28.785 to 1 significant figure?

A

A number just round it to the nearest 10. So the answer would be 30

16
Q

How many cm are in 1m^2?

A

10000

Because there are 100 cm in 1m and when you square you multiply the number by itself.

17
Q

How do you simplify ratios?

A

By dividing all the parts in the ratio by a common factor.

18
Q

How do you divide 672 by 1.6 without a calculator?

A

Multiply by ten to get 16 and 6720. Now use long or short division to divide 6720 by 16 to get your answer.

19
Q

How many km are in 5miles?

A

8