Showing posts with label tidu numbers. Show all posts
Showing posts with label tidu numbers. Show all posts

Monday, 19 February 2018

Solving addition and subtraction problems by making tidy number.

WALT - Solve addition and subtraction problems by making tidy number.


SUCCESS CRITERIA
  • I can make one number to a tidy number.
  • Solve the problem by either counting
forward or backward in tens.


I had $53 in my bank account and I saved $18 more.
How much money do I have?
(18 + 2 = 20) (53 - 2 = 51)   20 + 51 = 71.
Tim has $38 and his brother $27. How much money do they have in total?
(38 + 2 = 40) (27 - 2 = 25) 40 + 25 = 65.
There were 73 students in the library. Then 21 more students arrived at the library. How many students are in the library?
(73 - 3 = 70) (21 + 3 = 24) 70 + 24 = 94.
This is just part of what I did in Maths when we revise some of the addition and subtraction strategies.