Question

Use mental math to decide which equations are true. Drag the true equations into the box.

(1 point)
Put responses in the correct input to answer the question. Select a response, navigate to the desired input and insert the response. Responses can be selected and inserted using the space bar, enter key, left mouse button or touchpad. Responses can also be moved by dragging with a mouse.
true equations

Answer 1

I don’t see the list of equations — please paste the equations (or a screenshot) you’re asked about and I’ll mark which are true.

Meanwhile, here are quick mental-math tips you can use to decide truth:

- Compute both sides in your head and compare. Use shortcuts:
- Multiply by 10 then adjust (e.g., 9×6 = 60 − 6 = 54).
- Multiply by 5 = half of ×10 (e.g., 5×8 = 40).
- 11×n = 10n + n (e.g., 11×7 = 77).
- Square shortcuts: (n+1)² = n² + 2n + 1; common squares: 6²=36, 7²=49, 8²=64, 9²=81.
- Halves and doubles: use them to simplify fractions and products.
- For subtraction/addition, line numbers up mentally: 100 − 47 = 53, so 100 − 47 = 53 (true).
- For checking multiplication that’s near a round number: 24×25 = 600 (because 24×100÷4 = 600).
- If either side is an expression, simplify both sides fully before comparing.

If you paste the specific options I’ll tell you which to drag into the “true equations” box.