Rounding To the nearest 100

Rounding In this lesson we are looking at rounding numbers to the nearest 100. Rounding Rounding is used to approximate or estimate.

Rounding whole numbers Can you remember how to round numbers to the nearest 10? Identify the units digit. If the units digit is a 1, 2, 3 or 4 we round down. If the units digit is a 5, 6, 7, 8, or 9 we round up.

continued There is a similar pattern for rounding numbers to the nearest100 1) Identify the tens digit.

Onto the next step. continued 2) If the tens digit is a 0, 1, 2, 3 or 4 we round down to the nearest 100. continued Is it closer to 500 or 600? Is it closer to 400 or 500? Can you see that the units digit is not important when rounding numbers to 100?

Onto the final step. continued 3) If the tens digit is a 5, 6, 7, 8 or a 9 round up to the next hundred. continued Is it closer to 500 or 600? Is it closer to 600 or 700? Remember if a number ends in -50, although it is exactly halfway between the two hundred values we still round up!

Lets have ago at rounding to the nearest 100. continued Is it closer to 300 or 400? Is it closer to 600 or 700? Is it closer to 700 or 800?

And more… Is it closer to 100 or 200? Is it closer to 800 or 900? Is it closer to 900 or 1000?

continued Now without the number line!

Plenary Match these numbers to the nearest Choose 2 cards that when added together round to and 320 = 490

Rounding to the nearest 10,100 -Miniwbs -Markers -LET’S GO!

Round 19 to the nearest 10

Round 22 to the nearest 10

Round 83 to the nearest 10

Round 219 to the nearest 100

Round 342 to the nearest 100

Round 57 to the nearest 10

Round 743 to the nearest 10

Round 841 to the nearest 100

Round 44 to the nearest 10

Round 99 to the nearest 10

Round 350 to the nearest 100

Round 454 to the nearest 100

Round 516 to the nearest 10

Round 188 to the nearest 10

Round 975 to the nearest 100

Round 9709 to the nearest 100

Round 1902 to the nearest 10

Round 371 to the nearest 10

Round 3761 to the nearest 100

Round 8555 to the nearest 100

Round 1100 to the nearest 100

Round 8401 to the nearest 10

Homework STP 7A Pg 13 Exercise 1H Round to the nearest 100