Tuesday's maths - 2/6/20
The focus for the week is going to be on mental tips and strategies to help with addition and subtraction...
Yesterday the tip was how to add on 9 to any number. Today's tip is even simpler and quite quick; how to simply add 11 or 12. Just follow these easy steps:
1) Start with the number you are adding the 11 or 12 to.
2) Add on a ten (adding an extra one in the tens column).
3) Count on / add the remaining 1 (if adding 11) or 2 (if adding 12).
What you are basically doing is partitioning (breaking down) the number you are adding (11 or 12) and adding it on in chunks. See below for an example:
46 + 12
1) Start with 46 (the number that 12 is being added to).
2) Add on a ten, so 46 becomes 56 ( +1 in the tens column).
3) 56...57...58 (Added on the remaining 2).