6. Increase 27.4578 by 5.783  * 2 points A.33.2408
B.332.408
C.3.32408
D.3324.08
7. Take away 28.567 from the sum of 19.54 and 27.69  * 2 points A.18.663
B.1.8663
C.186.63
D.1866.3
8. Deduct 15.729 from the sum of 26.84 and 4.5. A.1.5611
B.15.611
C.156.11
D.1561.1
9. Add 15.729 to the difference of 26.84 and 4.5  * 2 points A.47.069
B.470.69
C.4.7069
D.4706.9
10. Reduce the sum of 78.451 and 69.354 by the sum of the 12.03 and 16.54  * 2 points A.11.9332
B.1193.32
C.119.332
D.1.19332 ​