5+10+10 5+5+5+10 5+5+5+5+5 5+20 Four ways.
15. 5 - -10 = 5 + 10 = 15 → 15 + -10 = 15 - 10 = 5
5 + (-10) = 5 - 10 = -5
Multiples of 5: 5, 10, 15Multiples of 10: 10, 20The LCM is 10.
10 + 10 + 10 + 5 + 5 +1 = 41.
25 different ways: 20, 20, 20, 20, 5 20, 20, 20, 10, 10, 5 20, 20, 20, 10, 5, 5, 5 20, 20, 20, 5, 5, 5, 5, 5 20, 20, 10, 10, 10, 10, 5 20, 20, 10, 10, 10, 5, 5, 5 20, 20, 10, 10, 5, 5, 5, 5, 5 20, 20, 10, 5, 5, 5, 5, 5, 5, 5 20, 20, 5, 5, 5, 5, 5, 5, 5, 5, 5 20, 10, 10, 10, 10, 10, 10, 5 20, 10, 10, 10, 10, 10, 5, 5, 5 20, 10, 10, 10, 10, 5, 5, 5, 5, 5 20, 10, 10, 10, 5, 5, 5, 5, 5, 5, 5 20, 10, 10, 5, 5, 5, 5, 5, 5, 5, 5, 5 20, 10, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 20, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 10, 10, 10, 10, 10, 10, 10, 10, 5 10, 10, 10, 10, 10, 10, 10, 5, 5, 5 10, 10, 10, 10, 10, 10, 5, 5, 5, 5, 5 10, 10, 10, 10, 10, 5, 5, 5, 5, 5, 5, 5 10, 10, 10, 10, 5, 5, 5, 5, 5, 5, 5, 5, 5 10, 10, 10, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 10, 10, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 10, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
Keep this in mind 75, 25, 10, and 5 are all divisible by 5 5x15 = 75; so adding 5, 15 times = 75 5X5 = 25 5x2 = 10 5x1 = 5 Take a look at the mathematical pattern and notice how the numbers split 25 + 25 + 25 25 + 25 + 10 + 10 + 5 25 + 25 + 10 + 5 + 5 + 5 25 + 25 + 5 + 5 + 5 + 5 + 5 25 + 10 + 10 + 10 + 10 +10 25 + 10 + 10 + 10 + 10 + 5 + 5 25 + 10 + 10 + 10 + 5 + 5 + 5 + 5 25 + 10 + 10 + 5 + 5 + 5 + 5 + 5 + 5 25 + 10 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 25 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 10 + 10 + 10 + 10 + 10 + 10 + 10 + 5 10 + 10 + 10 + 10 + 10 + 10 + 5 + 5 + 5 10 + 10 + 10 + 10 +10 + 5 + 5 + 5 + 5 + 5 10 + 10 + 10 + 10 + 5 + 5 + 5 + 5 + 5 + 5 + 5 10 + 10 + 10 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 10 + 10 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 10 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5
20 different ways ____________________________________________________________ There are 12 different ways - 20+20+10 20+20+5+5 20+10+10+10 20+10+10+5+5 20+10+5+5+5+5 20+5+5+5+5+5+5 10+10+10+10+10 10+10+10+10+5+5 10+10+10+5+5+5+5 10+10+5+5+5+5+5+5 10+5+5+5+5+5+5+5+5 5+5+5+5+5+5+5+5+5+5
12 1) 20 + 20 + 10 2) 20 + 20 + 5 + 5 3) 20+ 10 + 10 + 10 4) 20 + 10 + 10 + 5 + 5 5) 20 + 10 + 5 + 5 + 5 + 5 6) 20 + 5 + 5 + 5 + 5 + 5 + 5 7) 10 + 10 + 10 + 10 + 10 8) 10 + 10 + 10 + 10 + 5 + 5 9) 10 + 10 + 10 + 5 + 5 + 5 + 5 10) 10 + 10 + 5 + 5 + 5 + 5 + 5 + 5 11) 10 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 12) 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5
5+5+5+5+ 5+5+5+5+5+5 = 50 10+10+10+10+10 = 50 25+25 = 50 25+10+10+5 = 50 25+10+5+5+5 = 50 25+5+5+5+5+5 = 50 10+5+10+5+10+5+5 = 50
0.5 = 5/10
10 - 5 = 5 The difference between 10 and 5 is 5.
5+10+10 5+5+5+10 5+5+5+5+5 5+20 Four ways.
15. 5 - -10 = 5 + 10 = 15 → 15 + -10 = 15 - 10 = 5
5 + (-10) = 5 - 10 = -5
5-10 = -5
One method is (10×4)+(5×3) = 55 (or mentally add up from left to right).