Answer :

36+28= 64

36+10= 46
46+10= 56
56+1= 57
57+1= 58
58+1= 59
59+1= 60
60+1= 61
61+1= 62
62+1= 63
63+1= 64

And so, 36+10+10+1+1+1+1+1+1+1+1 is the least amount of tens and ones you will need to get to 64.

On a number line, you can:
1. Count ten notches and make a mark
2. Count count another ten notches and make a mark
3. Then count eight notches of one.
4. 10 + 10 + 8 (eight ones) gives you 28
5. Simply add 28 and 36

OR you can:

Starting on a number line that is numbered 1 to 64, start at 36 and do the same thing as above. After you're done counting on the number line, you should land on 64.

Hope this helped :)