You will now practice all the skills you learned in Unit 3. Check your work using the answer key at the end of the review.

1. Check out your subtraction facts.
   1. [latex]\begin{align*}5\\-2\\ \hline\\ \end{align*}[/latex]
   2. [latex]\begin{align*}8\\-7\\ \hline\\ \end{align*}[/latex]
   3. [latex]\begin{align*}3\\-1\\ \hline\\ \end{align*}[/latex]
   4. [latex]\begin{align*}9\\-5\\ \hline\\ \end{align*}[/latex]
   5. [latex]\begin{align*}18\\-9\\ \hline\\ \end{align*}[/latex]
   6. [latex]\begin{align*}11\\-4\\ \hline\\ \end{align*}[/latex]
   7. [latex]\begin{align*}13\\-5\\ \hline\\ \end{align*}[/latex]
   8. [latex]\begin{align*}10\\-5\\ \hline\\ \end{align*}[/latex]
   9. [latex]\begin{align*}6\\-6\\ \hline\\ \end{align*}[/latex]
   10. [latex]\begin{align*}14\\-8\\ \hline\\ \end{align*}[/latex]
   11. [latex]\begin{align*}16\\-7\\ \hline\\ \end{align*}[/latex]
   12. [latex]\begin{align*}12\\-9\\ \hline\\ \end{align*}[/latex]
   13. [latex]\begin{align*}17\\-9\\ \hline\\ \end{align*}[/latex]
   14. [latex]\begin{align*}9\\-3\\ \hline\\ \end{align*}[/latex]
   15. [latex]\begin{align*}13\\-6\\ \hline\\ \end{align*}[/latex]
   16. [latex]\begin{align*}15\\-8\\ \hline\\ \end{align*}[/latex]
2. Subtract across or horizontally.
   1. 8 − 6 =
   2. 12 − 5 =
   3. 10 − 10 =
   4. 9 − 8 =
   5. 11 − 6 =
   6. 8 − 4 =
   7. 7 − 3 =
   8. 14 − 9 =
3. Find the differences.
   1. [latex]\begin{align*}45\\-23\\ \hline\\ \end{align*}[/latex]
   2. [latex]\begin{align*}78\\-15\\ \hline\\ \end{align*}[/latex]
   3. [latex]\begin{align*}84\\-52\\ \hline\\ \end{align*}[/latex]
   4. [latex]\begin{align*}57\\-10\\ \hline\\ \end{align*}[/latex]
   5. [latex]\begin{align*}78\\-21\\ \hline\\ \end{align*}[/latex]
   6. [latex]\begin{align*}69\\-43\\ \hline\\ \end{align*}[/latex]
   7. [latex]\begin{align*}96\\-45\\ \hline\\ \end{align*}[/latex]
   8. [latex]\begin{align*}88\\-35\\ \hline\\ \end{align*}[/latex]
   9. [latex]\begin{align*}95\\-33\\ \hline\\ \end{align*}[/latex]
4. Find the differences.
   1. [latex]\begin{align*}583\\-163\\ \hline\\ \end{align*}[/latex]
   2. [latex]\begin{align*}799\\-265\\ \hline\\ \end{align*}[/latex]
   3. [latex]\begin{align*}629\\-305\\ \hline\\ \end{align*}[/latex]
   4. [latex]\begin{align*}847\\-406\\ \hline\\ \end{align*}[/latex]
   5. [latex]\begin{align*}978\\-252\\ \hline\\ \end{align*}[/latex]
   6. [latex]\begin{align*}797\\-652\\ \hline\\ \end{align*}[/latex]
   7. [latex]\begin{align*}765\\-243\\ \hline\\ \end{align*}[/latex]
   8. [latex]\begin{align*}854\\-344\\ \hline\\ \end{align*}[/latex]
   9. [latex]\begin{align*}536\\-314\\ \hline\\ \end{align*}[/latex]
   10. [latex]\begin{align*}897\\-246\\ \hline\\ \end{align*}[/latex]
   11. [latex]\begin{align*}669\\-238\\ \hline\\ \end{align*}[/latex]
   12. [latex]\begin{align*}769\\-564\\ \hline\\ \end{align*}[/latex]
5. Word problems.
   1. One week, Tiago changed 258 light bulbs in the building. The next week, Tiago changed 141 light bulbs. How many more bulbs did Tiago change the first week?
   2. Anoki drove 769 kilometres while his friend Dasan drove 534 kilometres on their trip. How many more kilometres did Anoki drive?

Answers to Unit 3 Review

1. 1. 3
   2. 1
   3. 2
   4. 4
   5. 9
   6. 7
   7. 8
   8. 5
   9. 0
   10. 6
   11. 9
   12. 3
   13. 8
   14. 6
   15. 7
   16. 7
2. 1. 2
   2. 7
   3. 0
   4. 1
   5. 5
   6. 4
   7. 4
   8. 5
3. 1. 22
   2. 63
   3. 32
   4. 47
   5. 57
   6. 26
   7. 51
   8. 53
   9. 62
4. 1. 420
   2. 534
   3. 324
   4. 441
   5. 726
   6. 145
   7. 522
   8. 510
   9. 222
   10. 651
   11. 431
   12. 205
5. 1. 117 light bulbs
   2. 235 kilometres