ROUNDING

Rounding is a math concept that is sometimes tricky for students. Some students will master the concept with ease, while others are often stumped by its more abstract nature. I encourage my students to think about rounding in conjunction with a roller coaster or a hill with a car. Numbers either roll over the hill (rounding up) or fall back down the hill (rounding down). The trick is to teach students to look, like a detective, at the CLUE the number leaves for you. This clue is the digit to the RIGHT of whatever place you are rounding to. For example:

Round 62 to the nearest TEN.

Look at the TENS place (6, value 60)

Look at the digit to the right of the tens place, in the ones place (2)

If the number to the right of the place being rounded is 5 or GREATER, round the number up. If the number is less than 5, round DOWN.

I ask students to always lay out two possibilities or choices. See the example below:

45 - round to the nearest ten

Choices: 40 or 50 (since rounding to the nearest ten, my choices must end in zeros)

Look at the tens place (4, value 40)

Look at the ones place - the digit is 5, therefore I will round up

The answer is 50

It often helps students to have a visual of a hill and even a paper car to move up and down the hill. The important steps to remember:

1) Think through both choices (rounding up or down)

2) Look at the place you are asked to round to

3) Look at the secret number to the RIGHT of the place you are rounding to

4) Decide if you should round UP or DOWN

I will post a video later in the week.