1A Rounding and estimating Learning intentions
Inter-year links
✔ I can round whole numbers.
Place value
Year 7
1A Place value
✔ I can assess the accuracy of estimation.
Year 9
1A Calculator skills
SA LE
Years 5/6
✔ I can estimate the results of simple calculations.
Place value
Place value charts can be used to determine the value of each digit in a number. Hundred Ten Thousands Hundreds thousands thousands 2
8
7
The place value of 3 is
3 000 000
The place value of 2 is
200 000
The place value of 8 is
80 000
The place value of 7 is
7000
The place value of 2 is
200
The place value of 6 is
60
The place value of 3 is
3
Ones
R
FO
3
Tens
2
6
3
T
Millions
3 2 8 7 2 6 3
N LY
-N
O
•
Rounding
D
R AF
T
•
Rounding a number involves replacing a number with an approximation that is simpler and easier to use in calculations. Using rounded numbers makes calculations less accurate. ➝ ‘Approximately equal’ is shown using the symbol ‘≈’. To round to the nearest thousand, place a box around the digit in the thousands place. ➝ If the digit to the right of the box is equal to or greater than 5, round up. ➝ If the digit to the right of the box is less than 5, round down.
O
•
•
12 600 ≈ 13 000 9 8 7 6 5
17 300 ≈ 17 000 4 3 2 1 0
Round up
Round down
Rounding to a number’s leading digit involves boxing the first digit and checking if the second digit is less than or greater than 5. Leading digit
123 456 = 123 456 ≈ 100 000
4 — OXFORD MATHS 8 VICTORIAN CURRICULUM
OXFORD UNIVERSITY PRESS No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means.
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21-Oct-21 18:11:10
