To find the complement of a 2-digit number, find the number that when added to the first digit will yield 9 and the number that when added to the second digit will yield 10.
If you want to change selection, open document below and click on "Move attachment"
pdf
owner:
feasthat - (no access) - Secrets of Mental Math (guidebook).pdf, p18
Summary
| status | not read | | reprioritisations | |
|---|
| last reprioritisation on | | | suggested re-reading day | |
|---|
| started reading on | | | finished reading on | |
|---|
Details