Rounding means making a number simpler but keeping its value close to what it was. The result is less accurate, but easier to use.

If this number is less than 5 (0, 1, 2, 3, 4) you leave your last digit as it is.

If it is 5 or more (5, 6, 7, 8, 9) you increase the value of your last digit by one.

Any digits after your place become zeros or are dropped off if they are to the right of the decimal point.

EXAMPLES...

For example, if we need to round 3270 to the nearest 100, we will check the tens place. In this case, it is 7, which means the digit in the hundreds place will be increased by 1.  The 2 will become 3 and the remaining digits to its right will become zero. Therefore, 3270 will be rounded up to 3300.

If you want to round 7.6 to the nearest whole number, we look at the last number - it is above or below 5? In this case it is above 5 therefore we give the 7 a shove up to 8. Therefore 7.6 is closer to 8. 

EXAMPLES...

For example, 25 is a square number because it's 5 lots of 5, or 5 x 5. This is also written as 52 (“five squared”). 100 is also a square number because it's 102 (10 x 10, or “ten squared”)

Index notation (or powers) is a way of expressing a product with the same factors. It is a short way of writing a number when it is multiplied by itself. 

The number that is being multiplied by itself is known as the 'base'.

The number written above the base is known as the 'index', 'power' or exponent'.