Unit 15 – The four operations
(a) Estimate the answer to 518 + 374. 518 rounds to
1
to the nearest 100
374 rounds to
to the nearest 100
+
=
(b) Copy and complete the calculation using the two different methods. 518 + 374 = 500 + + + + + = + + =
+ 300
+ 70 + 2
+ 2
518
Find the total. Write the calculation.
1
Try these. Make estimates first. (a) 629 + 238
2
(b) 229 + 638
(c) 729 + 265 (d) 709 + 265 What do you notice about the answers? Can you explain why?
189
9781380050687__text.indb 189
03/05/2022 10:20
Made with FlippingBook Learn more on our blog